JPH01228143A - Split of semiconductor wafer - Google Patents

Abstract

PURPOSE:To facilitate the formation of a small semiconductor element by a method wherein a vacuum seal of a semiconductor wafer is formed of a first vinyl chloride film and a second vinyl chloride film to be provided through a gel-like resin film which is hardly electrified with static electricity. CONSTITUTION:A semiconductor water 1 formed with grooves for split is vacuum sealed using a first vinyl chloride film 2, to which one surface of the wafer is adhered, and a second vinyl chloride film 4 to cover a gel-like resin film 3, which covers the other surface of the water 1, and the wafer 1 and a pressing force is applied to one surface of the wafer 1. That is, the film 3 can be comparatively removed easily from the surface of the wafer 1, split semiconductor elements 11 are adhered to the film 4 and a possibility that the elements 11 are removed is eliminated. Thereby, the formation of a semiconductor element of a small adhesion area is facilitated.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] This invention relates to a method of dividing a semiconductor wafer into individual semiconductor devices.

[Conventional technology]

The conventional method for dividing semiconductor wafers is: (1) reducing the overall thickness of the semiconductor wafer; ■Form dividing grooves (scribe lines) in semiconductor wafers.

(2) A pressing force is applied to the semiconductor wafer 8 to divide it into individual semiconductor elements. (2) Selecting a desired semiconductor element; at least the steps (2) to (3) are required.

Among these, the conventional method is known as a method for easily dividing the semiconductor element into individual semiconductor elements with a high yield, especially in the steps (1) and (2).

The contents will be explained in order of steps using FIGS. 5 to 7. Among them, Fig. 5 is a cross-sectional view showing the state after completion of vacuum sealing, Fig. 6 is a cross-sectional view showing the state after division is completed, and Fig. 7 is a cross-sectional view showing the state after completion of the vacuum sealing.
The figure is a cross-sectional view showing a state in which semiconductor elements are arranged at appropriate intervals. In the figure, (1) is a semiconductor wafer to be divided with dividing grooves formed therein, (2) is a first vinyl chloride film that adheres this semiconductor wafer, and (4) is a second vinyl chloride film that covers the semiconductor wafer. vinyl film,
(11υ is the semiconductor element in a divided state, and the two waves of the semiconductor element generated when the second vinyl chloride film is removed are the parts.

Hereinafter, the conventional method will be explained step by step.

[First step] In FIG. 5, the semiconductor wafer (1) is placed between the first vinyl chloride film (2) and the second vinyl chloride film (4), and the back side of the semiconductor wafer (1) is This semiconductor wafer (1) is vacuum-sealed with the semiconductor wafer (1) adhered to the first vinyl chloride film.

[Second step] A pressing force is applied to the semiconductor wafer (1) vacuum-sealed in the first step using a roller having a diameter corresponding to the size of the semiconductor element Qυ to separate the semiconductor elements q1.
) break process.

[Third step] Semiconductor element α divided in the above second step
The second vinyl chloride film (4
) only. At this time, the back surface of the semiconductor element Qυ is adhered to the first vinyl chloride film (2), as shown in FIG.

[Fourth step] The first vinyl chloride film (2
) is stretched until the distance between the semiconductor elements Ql) reaches a desired size, as shown in FIG.

[Fifth step] The first vinyl chloride film (2) is fixed in the stretched state described above.

The above method is the so-called sheet expansion method, in which the semiconductor elements αη remain aligned.
In addition, since the desired spacing is maintained, it is convenient to select the desired semiconductor element Qυ, and it is also possible to pick up the semiconductor element (b) using a machine, making it easier to assemble semiconductor elements. Automation also has many advantages.

[Aff to be Solved by the Invention] In the conventional semiconductor wafer dividing method as described above, in the second step, the second vinyl chloride film (4) that was in contact with the surface of the semiconductor element 1. After successfully removing the semiconductor element, place the divided semiconductor element 0 on the first vinyl chloride film (2) adhered to the back side of the semiconductor element.
The third step of keeping υ aligned is important. That is, as shown in FIGS. 5 and 6, the semiconductor element αυ
When peeling off the second vinyl chloride film (4) that is in contact with the surface of the semiconductor element Q〃, if the adhesive force between the second vinyl chloride film (4) and the semiconductor element qυ is too strong due to the adhesion effect due to electrostatic force, , the divided semiconductor element 0υ is attached to the second vinyl chloride film (4) and the second vinyl chloride film (4) is attached.
As shown in Figure 7, the teeth of the semiconductor element were removed along with the vinyl chloride film (4).
Tooth extractions that occur become unstable and cannot remain aligned. Particularly when the area of the semiconductor element q1) is small and the contact area between the back surface of the semiconductor element αυ and the first vinyl chloride film (2) is small, the teeth of the semiconductor element are extracted in the portion (2).
There are many conditions that can be seen when a tooth is extracted.

In order to prevent this, if the adhesive strength of the first vinyl chloride film (2) that adheres to the back surface of the semiconductor element αυ is strengthened, the teeth will be extracted in a better condition in the third step, but the individual When selecting and removing the semiconductor element a1), the adhesive force is strong and causes resistance during removal, making it difficult to remove the semiconductor element Ql) and further causing damage such as cracking or chipping to the semiconductor element Qυ.

On the other hand, if a film with weak adhesive strength is selected for the second vinyl chloride film (4) in contact with the surface of the semiconductor element αυ, the second vinyl chloride film (4)
When dividing into semiconductor elements Qυ in the step of , the first vinyl chloride film (2) and the second vinyl chloride film (4
) The elements collide with each other due to gaps between them.
This may cause you to overpay. The chips generated by this chipping may cause scratches on the surface of the device, and if they remain on the surface of the semiconductor device (11) after the fourth step, they may cause problems with the reliability of the device. Therefore, it is necessary to remove debris from the surface of the semiconductor element α.
Since these become so-called foreign particles, it is desirable that fewer chips occur, and even if they occur, it is desirable that they do not remain on the surface of the semiconductor element Qυ.

The present invention was made to solve these problems, and aims to take advantage of the advantages of the sheet expansion method and improve it to increase the yield of semiconductor devices.

[Means to solve the problem]

This invention includes a first vinyl chloride film bonded to one side of a semiconductor wafer in which dividing grooves are formed, and a gel-like resin film covering the other side of the semiconductor wafer, which covers the gel-like resin film and the semiconductor wafer. The method is characterized in that vacuum sealing is performed using a second vinyl chloride film, and then a pressing force is applied to one surface of the semiconductor wafer.

[Effect]

According to this invention, since the gel-like resin film is in close contact with the surface of the semiconductor wafer in the second step (break step), the generation of debris can be reduced, and even if a small amount of debris is generated, the break step At this time, these fragments sink into the gel-like resin film, so that when the gel-like resin film is removed from the semiconductor wafer, these fragments are also removed without remaining on the surface of the semiconductor wafer.

Moreover, this gel-like resin film can be relatively easily removed from the semiconductor wafer surface, and unlike conventional vinyl chloride film, when it is removed from the semiconductor element, it has an adhesion force with the semiconductor element due to the adhesion effect due to electrostatic force. There is no risk that the waves will be so strong that the divided semiconductor elements will adhere to the vinyl chloride film and be removed.

[Embodiments of the invention]

Hereinafter, a method for dividing a semiconductor wafer, which is an embodiment of the present invention, will be explained with reference to FIGS. 1 to 4.

Figure 1 of the inner box is an exploded perspective view to explain the vacuum seal, Figure 2 is a sectional view showing the state after the vacuum seal is completed, and Figure 3 is an exploded perspective view to explain the vacuum seal.
The figure is a cross-sectional view showing a state in which the gel-like resin film and the second vinyl chloride film have been removed after the division is completed, and FIG. 4 is a cross-sectional view showing a state in which the first vinyl chloride film is stretched and semiconductor elements are arranged at appropriate intervals. It is a diagram. In these figures, (1), (2), (4), and Oυ are the same as those used when explaining the conventional method, so their explanation will be omitted. (3
) is a gel-like resin film.

In FIG. 1, a semiconductor wafer (1) on which a desired active region is formed (for example, a gallium arsenide (Ga) on which a metal-semiconductor field effect transistor (MES FET) is formed)
As) wafer) is thinned to a desired thickness (for example, 130 μm), and the semiconductor element qυ is thinned to a desired size (for example, 0.0 μm).
4 mm opening), semiconductor wafers (1) (7)
After forming dividing grooves (scribe lines) on the surface using a diamond scriber, as shown in FIG.
), gel-like resin film (3), and second vinyl chloride film (4), and the semiconductor wafer (1) is vacuum-sealed.

That is, a semiconductor wafer (1) is placed on the first vinyl chloride film (2) so that its back surface is adhered,
Gel-like resin film (3) on vinyl chloride film (2)
(for example, one made by molding Tore Potting Resin 5R-1840 manufactured by Toshi Silicone Co., Ltd.) is placed so that the surface of the semiconductor wafer (1) is in contact with the gel-like resin film (3), and then the second vinyl chloride film is Layer the film (4). Thereafter, a vacuum pump is used to create a vacuum between the first vinyl chloride film (2) and the second vinyl chloride film (4) to complete vacuum sealing as shown in FIG. At this time, the gel-like resin film (3) needs to be large enough to cover at least the entire semiconductor wafer (1), and the second vinyl chloride film (4) needs to be large enough to cover the entire gel-like resin film (3). is necessary.

After vacuum sealing is completed, the first vinyl chloride film (2) on the back side of the semiconductor wafer (1) is pressed from the outside onto the semiconductor wafer (1) using a roller with a diameter corresponding to the size of the semiconductor element Ql). Pressure is applied to separate the semiconductor elements aυ (break process). Some of the fragments generated during this breaking process are retained in a state embedded in the gel-like resin film (3).

Next, the second vinyl chloride film (4) and gel-like resin film (3) are peeled off. First vinyl chloride film (
2) The divided semiconductor elements αυ are held in alignment as shown in FIG. Moreover, since the fragments generated during the breaking process are retained in the gel-like resin film (3), they are removed from the surface of the semiconductor element QU when the gel-like resin film (3) is peeled off.

After that, by stretching the first vinyl chloride film (2), the semiconductor elements αυ remain aligned accordingly.
Moreover, they are arranged as shown in FIG. 4 with appropriate spacing between them. In this way, by holding the first vinyl chloride film (2) in a stretched state, a desired semiconductor element aυ can be easily selected.

This invention provides a semiconductor wafer (1) with a first vinyl chloride film (2) and a second vinyl chloride film (4) interposed through a gel-like resin film (3) that is not easily charged with static electricity.
By forming a vacuum seal, it is particularly easy to form a semiconductor element with a small shape, that is, a semiconductor element with a small bonding area. In addition, it has the effect of reliably removing fragments generated when the semiconductor wafer (1) is divided into semiconductor elements αυ from the surface of the semiconductor elements αυ, improving the reliability of the semiconductor elements and improving the quality of the semiconductor elements. It also greatly contributes to improving yield.

In the above embodiment, G is used as the semiconductor wafer (1).
a Although the As wafer has been described, it is not limited to this.

An example of the gel-like resin film (3) is a silicone resin film. An example of a method for creating this gel-like resin film is shown below. That is, Torre Potting Resin 5H
-1840 (trade name manufactured by Toshi Silicone Co., Ltd.) is prepared, and this potting resin is mixed in a weight ratio of 10 parts to 1 part curing agent and thoroughly mixed. The silicone resin after mixing is in a sol state.

Store this sol-like silicone resin in a suitable container (for example, a plastic container with an internal size of 60 cm in length x 60 cm in width).
It is sufficient if the i*X depth is about 5 m. ) and slowly pour it into the container until it reaches about 1/3 to 1/2 of the depth. After injecting, dry under appropriate conditions in a clean oven or other dust-free place to form a gel. Thereafter, by removing this gel-like resin film from the container, a gel-like resin film (3) as described in the above embodiment can be obtained. Although the size of the container has been specifically described as an example for making the gel-like resin film (3) described above, this container is not limited to that size, and can be used for semiconductor wafers to which the present invention is applied. It is sufficient that the container is large enough to completely cover (1), and more preferably, the bottom surface of the container into which the sol-like resin film is injected has few irregularities.

Further, in the above embodiment, a resin film in a gel state is formed by molding a resin in a sol state, and this is used. However, the present invention is not limited to this. It's okay. The minimum conditions in this case are: ■ The gel-like resin film is not easily charged with static electricity; ■ It has a size that can completely cover the semiconductor wafer to be divided; ■ It has no negative effect on the semiconductor wafer. (1) The semiconductor element must be easily removed; (2) It must be possible to remove attached semiconductor wafer fragments, dust, etc.

〔Effect of the invention〕

As explained above, this invention provides a first vinyl chloride film bonded to one side of a semiconductor wafer in which dividing grooves are formed, and covers the other side of this semiconductor wafer with a gel-like resin film. Since the film and the semiconductor wafer are covered with a second vinyl chloride film, and the semiconductor wafer and gel-like resin film are vacuum-sealed by both vinyl chloride films, the pieces generated when the semiconductor wafer is divided are removed from the semiconductor wafer. It can be sunk into the gel-like resin film in contact with the surface and removed at the same time as the gel-like resin film is removed. Moreover, when removing this gel-like resin film, there is no need to remove some of the semiconductor elements, and it is possible to maintain the semiconductor elements in a divided state. As a result, it becomes possible to arrange semiconductor elements at desired intervals, and there is an effect that it becomes possible to divide semiconductor wafers into semiconductor wafers with good workability.

[Brief explanation of the drawing]

Figures 1 to 4 are diagrams showing a method for dividing a semiconductor wafer according to an embodiment of the present invention. Figure 1 is an exploded perspective view to explain vacuum sealing, and Figure 2 is an exploded perspective view after vacuum sealing is completed. 3 is a sectional view showing the state in which the gel-like resin film and the second vinyl chloride film are removed after the division is completed, and FIG. 4 is a sectional view showing the state in which the first vinyl chloride film is stretched and the semiconductor element is FIG. 3 is a cross-sectional view showing a state in which they are arranged at appropriate intervals. Figures 5 to 7 are diagrams showing a conventional semiconductor wafer dividing method, in which inner cylinder Figure 5 is a sectional view showing the state after vacuum sealing is completed, and Figure 6 is a sectional view showing the state after division is completed. ,
FIG. 7 is a sectional view showing a state in which semiconductor elements are arranged at appropriate intervals. In the figure, (1) is the semiconductor wafer, (2) is the first vinyl chloride film, (3) is the gel-like resin film, and (4) is the first vinyl chloride film.
is the second vinyl chloride film, αV is the semiconductor element, (
In b), the semiconductor elements are partially exposed. In each figure, the same reference numerals indicate the same or corresponding parts. Agent: Masuo Oiwa, Patent Attorney Figure 1, Figure 2, Figure 1, Figure 2, Figure 4, Figure 2, Figure 4. Figure 5 Figure 6 Figure 7

Claims (1)

[Claims] One side of the semiconductor wafer on which dividing grooves are formed is first
a step of adhering the other side of the semiconductor wafer to a vinyl chloride film, a step of covering the other side of the semiconductor wafer with a gel-like resin film, a step of covering the gel-like resin film and the semiconductor wafer with a second vinyl chloride film, and a step of covering the first and second vinyl chloride films. vacuum sealing the semiconductor wafer with a vinyl chloride film;
A method for dividing a semiconductor wafer comprising the step of applying a pressing force to one surface of the semiconductor wafer and dividing the semiconductor wafer along the grooves.