JPH09306873A - Wafer division system - Google Patents

Abstract

(57) Abstract: When a wafer is divided into two or more blocks, the street address to be cut is recognized, and the block can be identified at a later date and the mapping data can be effectively used. A wafer dividing system is provided. A wafer dividing system for dividing a wafer having a plurality of semiconductor chips formed by streets into two or more blocks.
When dividing into the above blocks, the address of the street to be cut is recognized, block data for specifying the block by this address is created and registered in the CPU. This block data includes mapping data, and after dicing the block into individual semiconductor chips, in the step of picking up individual chips, only the required semiconductor chips are picked up using the mapping data.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wafer dividing system for dividing a wafer having a plurality of IC chips formed thereon into two or more blocks.

[0002]

2. Description of the Related Art In the manufacture of semiconductor chips such as ICs, a plurality of chips formed on a single silicon wafer (hereinafter referred to as a wafer) are tens to hundreds of tens of microns (μ).
m) Individually divided by scribe streets or scribe lines (hereinafter referred to as streets) running in the x and y axis directions having a width. Wafers that have completed the chip manufacturing process are cut along the streets (hereinafter referred to as dicing) by a high-speed rotating blade with diamond grains embedded by a device called a dicing saw in the subsequent package assembly process, and divided into individual chips. To be done. The dicing saw is mounted on the cassette mounting area a which moves up and down as shown in FIG.
A cassette c accommodating a plurality of (adhesive tape (hereinafter referred to as tape) N fixed to the frame F) is placed,
The wafer W is unloaded from the cassette c into the standby area d by the loading / unloading means b, and the chuck table t (the wafer W is directly placed on the chuck table t manually or automatically by the transfer means e having a swing arm). This chuck table t
Is moved and positioned on the alignment means g for alignment, and then dicing is performed by the cutting means h equipped with a rotary blade.

However, recently, a wafer may be divided into two or more blocks before dicing. This is because the number of chips formed on one wafer increases with the large diameter of the wafer and the miniaturization of chips, and one wafer requires one assembly manufacturing unit in the subsequent package assembly process. It occurs too much compared to the number of chips. In such a case, the wafer is divided into a plurality of blocks, only some of the blocks are diced according to the number of chips required, and the remaining blocks are stored as an inventory for later use.

[0004]

When storing a block of a divided wafer, a record is kept about the block so that the characteristics of the chip (quality, size, key pattern for alignment, etc.) can be understood. There was no record of which street they cut off. Therefore, it is possible to determine which part (area) of the original wafer the block is when the storage block is taken out at a later date and so-called die bonding is performed to mount the diced chip on the lead frame or the like during dicing or package assembly. In particular, there is a problem that the mapping data of the wafer in which the goodness and the badness of the chip necessary for die bonding are recorded cannot be used. There is also a problem that the divided blocks of the wafer cannot be placed in an appropriate positional relationship with respect to the frame F held via the tape N. Therefore, the present invention is a wafer division system in which, when a wafer is divided into two or more blocks, the street address to be cut is recognized, the block is specified at a later date, and the mapping data can be effectively used. The challenge is to provide.

[0005]

As a means for technically solving the above problems, the present invention provides a wafer having a plurality of semiconductor chips divided by streets.
A wafer dividing system for dividing a wafer into the above blocks, which when a wafer is divided into two or more blocks, recognizes an address of a street to be cut and creates block data for specifying the block by this address. The division system of is the gist. Further, the correlation between the characteristic pattern on the wafer and the street address is registered in the storage means provided in the dicing saw, and the street address to be cut by detecting the characteristic pattern by the alignment means. Is recognized and registered in the storage means as block data, the streets to be cut are in the x-axis direction and the y-axis direction, and information regarding good or bad semiconductor chips is registered in the storage means as wafer mapping data. That is, the mapping data for each block is recognized as a part of the block data according to the street address to be cut, the block after division is stored as inventory with the block data, An identification display such as a bar code is provided, and this identification display identifies the block. The lock data can be recognized, after dicing the block into individual semiconductor chips, in the step of picking up the individual semiconductor chips, it is an Abstract that, the block data is utilized.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below in detail with reference to the accompanying drawings. In FIG. 1, reference numeral 1 denotes a semiconductor wafer, on which a plurality of semiconductor chips 2
Are separated by a predetermined street width and are vertically and horizontally arranged at a predetermined pitch. A case where the wafer 1 is divided into four blocks by streets (α) parallel to the x axis and streets (β) parallel to the y axis will be described.

Generally, the dicing saw (FIG. 6) can cut along any street of the wafer, but it is possible to accurately know the number of the street from the edge of the wafer, that is, the street address. While not cutting. A predetermined step is required to recognize the address of the street to be cut, and the step of recognizing the addresses of the streets (α) and (β) to be cut will be specifically described below.

First, as a prerequisite step, step: an address is set on a street formed with a predetermined width and pitch on the wafer 1, and a correlation with the street pitch is registered in a storage means (not shown). . In the example of FIG. 1, the addresses of the y-axis streets (streets parallel to the y-axis) are represented by x coordinates, and the addresses 0 (x ₀ ) to 18 (x ₁₈ ).
Up to x-axis streets (streets parallel to the x-axis) are represented by y-coordinates, and are set from address ₀ (y ₀ ) to address 16 (y ₁₆ ) respectively, and the correlation with the street pitch of the x-axis and the y-axis Register the relationship. Step: Alignment mark M (M _A , M _B , M _C
And M _D ) (FIG. 1), for example, a characteristic pattern such as M _B is registered in the storage means together with the correlation between the address (x ₃ , y ₁₃ ) of the pattern and the street address.

As a step for cutting, step: frame F through tape N as shown in FIG.
The wafer 1 placed on the wafer is pre-aligned and held on the chuck table t of the dicing saw. Step: Move the chuck table t to move the wafer 1
Is positioned immediately below the optical alignment means g. Step: Detect the characteristic pattern (alignment mark M). Step: Address of characteristic pattern, for example, x-axis street address (y ₁₃ ) and street pitch (for example, 5 m)
m) and the movement distance to the address (y ₈ ) of the x-axis street (α) to be cut ((13-8) × 5 m
m = 25 mm), the street (α) to be cut is positioned on the alignment means g, and the street (α) is precisely aligned by pattern matching or the like. Step: With respect to the y-axis street (β) to be cut, the street (β) to be cut is positioned on the alignment means g based on the address of the characteristic pattern and the like by the same method as the step, and the street (β) is subjected to pattern matching or the like. ) Precision alignment. In addition, step,
In the case of, the street (α) to be cut,
The address (β) needs to be registered in the storage means by the operator in advance.

Step: Street (α) address (y
₈ ), block data for specifying each of the blocks divided into four based on the address (x ₉ ) of the street (β) is created and recorded in the storage means. For example, if the blocks divided into four as shown in FIG. 1 are (A) to (D), the respective block data are as follows. Block _{(A) = (x 9 ~x} 18, y 8 ~y 16) block _{(B) = (x 0 ~x} 9, y 8 ~y 16) block _{(C) = (x 0 ~x} 9, y 0 ~ Y ₈ ) Block (D) = (x _{9 to} x ₁₈ , y _{0 to} y ₈ ) Step: Cutting street (α) and street (β) into four blocks, and block data for each block Leave. The block data is specified by the coordinates of the street, but the block data does not always match the coordinates of the mapping data that specifies a chip such as good or bad. Therefore, it is necessary to generate a correlation between the street coordinates and the mapping data coordinates and replace the mapping data with the street coordinates. Thereby, the mapping data can be recognized by the block data.

Incidentally, instead of step ~, the following steps '~' may be replaced. Step ': x-axis street (α) to be cut arbitrarily
After performing precise alignment by pattern matching or the like by the alignment means g, the characteristic pattern M is detected, and the address of the x-axis street (α) is recognized based on the address of the characteristic pattern. Step ': arbitrary y-axis street (β) to be cut
After performing the precision alignment by the pattern matching or the like by the alignment means g, the characteristic pattern M is detected, and the address of the y-axis street (β) is recognized based on the address of the characteristic pattern. Note that steps ','
In the case of 1, it is not necessary to register the addresses of the streets (α) and (β) to be cut in the storage means in advance.

In this way, when dividing a wafer into two or more blocks, it is possible to recognize the address of the street to be cut and create block data for specifying the block by this address. Further, the correlation between the characteristic pattern (alignment mark M) on the wafer and the street address is registered in the storage means, and the street to be cut by detecting the characteristic pattern (alignment mark M) by the alignment means g. The address is recognized and registered in the storage means as block data. A block of wafers stored as an inventory is not limited to this, but is fixed to a frame F via a tape N as shown in FIGS. 2 to 5, and block data is stored in the frame F or the tape N, respectively. Identification indicators 3a to 3d such as bar codes that can be pulled out from are attached. still,
When a block obtained by dividing a wafer is stored in a bag or the like, it is important to attach an identification mark for extracting the block data for identifying the block together. It is also possible to put a memo in which the block data is recorded. According to such data, when the divided blocks are arranged on the frame F via the tape N, the divided blocks are arranged with respect to a predetermined reference point of the frame F, for example, the notch Z at the lower left of the frame F. It can be set to an appropriate positional relationship.

[0013] In FIG. 2, when reading the identification 3a block (A) for block data (x ₉ ~x
₁₈ , y _{8 to} y ₁₆ ) can be retrieved from the storage means. As a result, it is found that this block (A) is in the upper left region of the original wafer 1 divided into four parts.

Similarly, the block (B) in FIG. 3 is in the upper right area, and the block (C) in FIG. 4 is in the lower right area.
It can be known that the block (D) in FIG. 5 belongs to the lower left area by pulling out each block data from the storage means via the identification displays 3b to 3d.

Explaining the procedure for taking out and dicing the blocks stored as the stock at a later date, the identification marks 3a to 3d such as the bar code displayed on the frame F or the tape N are detected by a bar code reader or the like. , Calls the block data recorded in the storage means. It is recognized that the block is the block (A) in the original wafer 1 as shown in FIG. 2, for example. x-axis street, for example, street (y address ₉ )
Is detected by the alignment means g, and rough alignment, that is, pre-alignment is performed. A predetermined pattern (a pattern arbitrarily designated in the chip for alignment) in the block is detected, and precision alignment is performed by the alignment means g by pattern matching or the like. Dicing is sequentially performed with the cutting means h from the x-axis street address y ₉ to y ₁₆ . The chuck table t is rotated by 90 degrees, and the y-axis street addresses x ₁₀ to x ₁₈ are sequentially diced by the cutting means h. Finish dicing. In addition, when dicing a block stored in a bag or the like, the block is arranged on a frame via a tape, and the identification mark put on the block is attached to the frame or the tape, and the blocks shown in FIGS. 5
Perform the steps from to in the state shown in.

Next, the relationship between the divided blocks and the mapping data will be described. Although not necessarily limited, the semiconductor chip 2 formed on the wafer 1 has a x-value because a correlation between mapping data coordinates that specify the semiconductor chip 2 and street coordinates is generated.
All are displayed in coordinates depending on the addresses of the axis street and the y-axis street. For example, as shown in FIG. 1, defective semiconductor chips C _{1 to} C ₇ are displayed in the coordinates. C ₁ (x ₁₂ , y ₁₃ ) C ₂ (x ₅ , y ₁₂ ) C ₃ (x ₁₀ , y ₈ ) C ₄ (x ₃ , y ₆ ) C ₅ (x ₁₄ , y ₄ ) C ₆ (x ₄ , Y ₃ ) C ₇ (x ₈ , y ₀ ), in FIG. 1, the address of the y-axis street is determined with reference to the first chip on the orientation flat 1 a (hereinafter referred to as “orifla”), and it is rotated by 90 ° with respect to the orientation flat 1 a. Although the address of the x-axis street is determined with reference to the rightmost chip at the position, it is not limited to this, and the address may be determined with reference to the alignment mark M and other characteristic chips (x ₀ , y ₀ ). You can

Information about defective products of the semiconductor chip is registered in the storage means as mapping data.
The mapping data for each block is recognized according to the street address to be cut and is made a part of the block data.
That is, each block includes mapping data as a part of the block data.

Therefore, according to the mapping data of the block (A) shown in FIG. 2, defective semiconductor chips C ₁ and C
_3, it is found that the block (B) shown in FIG. 3 also contains the defective semiconductor chip C ₂ , and the block (C) shown in FIG. 4 also contains the defective semiconductor chip C.
_{It is found that 4} , C ₆ and C ₇ are included, and the defective semiconductor chip C ₅ is included in the block (D) shown in FIG.

When any of the blocks stored as stock as described above is taken out at a later date and diced, the semiconductor chip is picked up when it is mounted on a lead frame or the like by a die mounter after the dicing. By reading the identification display, a semiconductor chip such as a defective product can be recognized based on the mapping data registered in the storage means in advance. Therefore, only the required semiconductor chip can be picked up by a die mounter or the like.

A procedure for picking up a semiconductor chip after dicing will be described. A dicing-completed block is loaded into a die mounter or the like. An identification display such as a bar code displayed on the frame or on the tape is detected by a reader or the like and the block data is called. For example, it is recognized that it is the block (A) region of the wafer. x-axis street (y ₈ ) and y-axis street (x
₉ ) is detected by the detection means. Unnecessary semiconductor chips C ₁ (x ₁₂ , y ₁₃ ) and C ₃ based on the wafer mapping data
Except for (x ₁₀ , y ₈ ), only required semiconductor chips such as non-defective products are picked up and placed on a lead frame or the like. Pickup ends.

Conventionally, when the wafer is divided, the positional relationship with the semiconductor chip is unknown and the mapping data cannot be used. However, according to the present invention, since the positional relationship of the semiconductor chip is clear even after the division, mapping is performed. The data can be used, and the processing capacity will be significantly improved. In the present invention, the x-axis street and the y-axis street are referred to as addresses, but in short, it suffices to be able to recognize the position of the street on the wafer. address"
It is included in the concept of.

[0022]

As described above, according to the present invention,
When a wafer is divided into two or more blocks and stored as inventory, the street address where the wafer is cut is recognized and registered as block data in the storage means. Therefore, when the block is taken out and diced at a later date, the street data is used. It is possible to efficiently perform the dicing work by finding the address of. Also, since the semiconductor chip formed on the wafer is recognized in the address in association with the street and registered in the storage means as the mapping data, after the block is taken out and diced at a later date, when the semiconductor chip is picked up by a die mounter or the like, It is possible to effectively use the mapping data and efficiently pick up only the necessary semiconductor chips.

[Brief description of drawings]

FIG. 1 shows an embodiment of the present invention, and is an explanatory diagram when a wafer is divided into four.

FIG. 2 is a plan view showing a state in which the block (A) is stored.

FIG. 3 is a plan view showing a state in which the block (B) is stored.

FIG. 4 is a plan view showing a state in which the block (C) is stored.

FIG. 5 is a plan view showing a state in which the block (D) is stored.

FIG. 6 is a perspective view showing an example of a dicing saw.

[Explanation of symbols]

 1 ... Wafer 1a ... Orientation flat 2 ... Semiconductor chips 3a-3d ... Identification display

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Kazuma Sekiya 2-14-3 Higashi-Kotani, Ota-ku, Tokyo Inside Disco Co., Ltd. (72) Inventor Katsuji Negishi 2-3-14 Higashi-Kotani, Ota-ku, Tokyo Shares Company disco

Claims (7)

[Claims] 1. A wafer division system which divides a wafer having a plurality of semiconductor chips divided by streets into two or more blocks, wherein when a wafer is divided into two or more blocks, A wafer division system that recognizes an address and creates block data to identify a block by this address. 2. A correlation between a characteristic pattern on a wafer and a street address is registered in a storage means,
2. The wafer dividing system according to claim 1, wherein the alignment means detects a characteristic pattern, recognizes the street address to be cut, and registers it as block data in the storage means. 3. The street to be cut is in the x-axis direction and y.
The wafer dividing system according to claim 1, wherein the wafer dividing system is in the axial direction. 4. Information relating to good or bad of a semiconductor chip is registered in a storage means as wafer mapping data, and mapping data for each block is recognized depending on an address of a street to be cut and used as a part of the block data. The wafer dividing system according to claim 1, 2, or 3. 5. The wafer dividing system according to claim 1, wherein the divided blocks are stored as inventory together with block data. 6. The wafer dividing system according to claim 5, wherein the block to be stored is provided with an identification display such as a bar code and the block data of the block can be recognized by the identification display. 7. The block data is used in the step of picking up individual semiconductor chips after dicing the blocks into individual semiconductor chips.
2. The wafer dividing system according to any one of 2, 3, 4, 5, and 6.