JP2869170B2 - Semiconductor chip pickup method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Summary] The present invention relates to a method for picking up a semiconductor chip, and more particularly to a method for picking up a semiconductor chip for correcting a deviation between a direction of an edge line of the semiconductor chip and a feed direction of a stage. By reading the coordinates of the corners of the three semiconductor chips formed above, each time the stage moves by the feed amount calculated from these coordinates, the stage is moved by the correction amount to shift the position. In order to provide a method for picking up a semiconductor chip to be corrected, a semiconductor chip formed on a semiconductor wafer mounted on a stage is moved from the stage to a position where the semiconductor chip is processed using a transfer tool. In a device for transporting the semiconductor chip, a semiconductor chip pickup method for matching the center of the semiconductor chip and the transport tool,
The reference coordinates A, B, and C in which straight lines connecting them are orthogonal to each other are defined on the stage described above, the AB direction is the X axis, and the BC is the BC direction.
With the direction being the Y axis, the coordinates (X ₁ , Y ₁ ) of the corner of the semiconductor chip near the reference coordinate A are read, and the coordinates (X ₂ , Y ₂ ) of the corner of the semiconductor chip near the reference coordinates B and C are read.
And (X ₃ , Y ₃ ) are read, and the coordinates (X ₁ , Y ₁ ), (X ₂ , Y ₂ ) and (X ₃ , Y ₃ ) of each corner of the semiconductor chip are read.
From Y ₃ ), an X-axis pitch feed amount, a Y-axis correction amount at the time of X-axis feed, a Y-axis feed amount, an X-axis correction amount at the time of Y-axis feed are calculated. Calculating the coordinates of the center of the semiconductor chip from the outer dimensions of the semiconductor chip, moving the stage to move the center to coincide with the center of the transfer tool, and transferring the semiconductor chip, and moving in the X-axis direction. When the stage is fed, each time the stage is fed in the X-axis direction by the X-axis pitch feed amount, the X
In the case of moving the stage in the Y-axis direction by moving the stage in the Y-axis direction by the Y-axis correction amount at the time of axis feed and feeding the stage in the Y-axis direction, the stage is moved in the Y-axis direction by the Y-axis pitch feed amount. Each time the semiconductor chip is fed in the X-direction, the semiconductor chip is moved in the X-axis direction by the X-axis correction amount at the time of the Y-axis feed to convey an adjacent semiconductor chip.
The semiconductor chip is accurately picked up by the transfer tool while correcting the inclination angle between the X and Y axes and the edge line of the semiconductor chip.

[Industrial applications]

The present invention relates to a semiconductor chip pickup method,
In particular, the present invention relates to a semiconductor chip pickup method for correcting a deviation between a direction of an edge line of a semiconductor chip and a feeding direction of a stage.

In a conventional die bonder or chip transfer device, when picking up a semiconductor chip formed on a semiconductor wafer, the semiconductor chip is picked up by correcting the position to one chip feed.

Under the circumstances described above, there is a demand for a semiconductor chip pickup method capable of picking up a semiconductor chip without correcting the position of each semiconductor chip.

[Conventional technology]

A conventional semiconductor chip pickup method will be described in detail with reference to FIG.

First, as shown in FIG. 3 (a), a semiconductor wafer 1 which is affixed to a cutting tape and fully cut into individual semiconductor chips 2 is mounted on the surface of a stage 3 at a semiconductor wafer mounting position. The stage 3 is moved to a pickup position of the semiconductor chip.

In this position, the transfer tool 4 is located directly above the center of the stage 3 in a normal apparatus.

The magnification of a lens of an optical system (not shown) used for recognizing the position of the semiconductor chip 2 is one chip on a display unit that displays an image of the semiconductor chip 2, for example, a CRT display device 5 as shown in FIG. Is adjusted by setting the magnification to be displayed.

An X, Y direction alignment reference line (X) 5a and an alignment reference line (Y) 5b provided on the CRT display device 5;
Edge line (X) 2a and edge line (Y) of the image of semiconductor chip 2 at both ends of semiconductor wafer 1 displayed on the display device
The shift of the tilt from 2b is detected, and the stage 3 is rotated by this tilt angle to eliminate the shift of this tilt.

By doing so, the edge line (X) of the semiconductor chip 2
2a and the edge line (Y) 2b coincide with the X and Y feed directions of the stage 3.

Next, the stage 3 is moved so that the semiconductor chip 2 to be picked up first comes directly below the transfer tool 4.
Here, the general outer shape and position of the semiconductor chip 2 are recognized.

Here, the presence or absence of a defective mark is detected, the mounting table 3 is moved, and the position is corrected so that the center of the semiconductor chip 2 and the center of the transfer tool 4 exactly match. To pick up.

Thereafter, the mounting table 3 is moved by one chip so that the semiconductor chip 2 to be picked up next comes directly below the transfer tool 4, where the outline and position of the semiconductor chip 2 are recognized, and the defective mark is detected. After detecting the presence / absence, the semiconductor chip 2 to which the defective mark is attached is skipped, and then the stage 3 is moved to correct the position so that the center of the semiconductor chip 2 and the center of the transfer tool 4 exactly match. Then, the semiconductor chip 2 is picked up by the transfer tool 4.

Such movement of the stage 3, recognition of the outline and position of the semiconductor chip 2, detection of the presence or absence of a defective mark,
Accurate position correction between the center of the semiconductor chip 2 and the center of the transfer tool 4 is performed, and the pickup of the semiconductor chip 2 by the transfer tool 4 is repeatedly performed for all the semiconductor chips 2.

[Problems to be solved by the invention]

In the conventional semiconductor chip pickup method described above, the magnification of the lens of the optical system used for recognizing the position of the semiconductor chip, so that one chip is displayed on the display unit that displays the image of the semiconductor chip, The magnification must be set and adjusted according to the size of the semiconductor chip,
Each time the stage is moved by one chip, the position of each semiconductor chip must be accurately corrected. This requires a lot of time, and lowers the operation rate of the device. was there.

From the above situation, the present invention reads the coordinates of the corners of the three semiconductor chips formed on the semiconductor wafer, and corrects each time the stage moves by the feed amount calculated from the coordinates. It is an object of the present invention to provide a method of picking up a semiconductor chip for correcting a positional shift by moving a mounting table by an amount.

[Means for solving the problem]

According to the semiconductor chip pickup method of the present invention, a semiconductor chip formed on a semiconductor wafer mounted on a mounting table is transferred from the mounting table to a position for processing the semiconductor chip using a transfer tool. In the apparatus, there is provided a semiconductor chip pick-up method for matching the center of the transfer tool with the center of the semiconductor chip, the reference coordinates A, B and C of three points on which the straight lines connecting the transfer tools are orthogonal to each other. , The AB direction is the X axis, the BC direction is the Y axis, the corner coordinates (X ₁ , Y ₁ ) of the semiconductor chip near the reference coordinates A, and the semiconductor chips near the reference coordinates B and C. The coordinates (X ₂ , Y ₂ ) and (X ₃ , Y ₃ ) of the corner of the semiconductor chip are read, and the coordinates (X ₁ , Y ₁ ), (X ₂ , Y ₂ ) and (X ₃ , Y ₃ )
The X-axis pitch feed amount, the Y-axis correction amount at the time of the X-axis feed, the Y-axis feed amount, the X-axis correction amount at the time of the Y-axis feed are calculated, and the coordinates of the corner of the semiconductor chip at which pickup is started, and The coordinates of the center of the semiconductor chip are calculated from the external dimensions, the stage is moved, the center is aligned with the center of the transfer tool, the semiconductor chip is transported, and the stage is sent in the X-axis direction. In this case, each time the stage is fed in the X-axis direction by the X-axis pitch feed amount, the stage is moved in the Y-axis direction by the Y-axis correction amount at the time of the X-axis feed, and the adjacent semiconductor chip is transported. When the stage is fed in the axial direction, every time the stage is fed by the Y-axis pitch feed amount in the Y-axis direction,
The adjacent tool is transported by moving it in the X-axis direction by the X-axis correction amount at the time of axis feed, and the transfer tool is adjusted while correcting the tilt angle between the X and Y axes of this stage and the edge line of the semiconductor chip. To pick up the semiconductor chip.

[Action]

That is, in the present invention, the coordinates of the corners of three semiconductor chips formed on the semiconductor wafer are read, and each time the stage moves by the feed amount calculated from these coordinates, the stage is moved by the correction amount. By moving and correcting the displacement, the semiconductor chip can be accurately picked up by the transfer tool.

〔Example〕

Hereinafter, an embodiment of the present invention will be described in detail with reference to FIGS.

First, as shown in FIG. 1 (a), a semiconductor wafer 1 attached to a cutting tape and fully cut into individual semiconductor chips 2 is mounted on the surface of a stage 3, and the position of the semiconductor chip 2 is recognized. The coordinates (X ₁ , Y ₁ ) of the corner 1 and the point 1 of the semiconductor chip 2 near the reference coordinates A are read by using a lens of an optical system (not shown) used for this.

Next, the stage 3 is moved so that the lens of the optical system is located near the reference coordinates B, and the coordinates (X ₂ , Y ₂ ) of the corner 2 of the semiconductor chip 2 near the reference coordinates B are determined. read.

Then, the stage 3 is moved so that the lens of the optical system is located near the reference coordinates C, and the coordinates (X ₃ , Y ₃ ) of the corner 3 of the semiconductor chip 2 near the reference coordinates C are read. .

The coordinates (X ₁ , Y ₁ ), (X ₂ ,
The following calculation is performed using Y ₂ ) and (X ₃ , Y ₃ ) to calculate the X-axis pitch feed amount, the Y-axis correction amount during X-axis feed, the Y-axis feed amount,
The X-axis correction amount at the time of Y-axis feed is calculated.

In the present embodiment in which the point 1 and the point 2 are 7 pitches apart and the point 2 and the point 3 are 8 hitches apart, first, X ₂ −X _{1 is set} to the dimension X _CH of the semiconductor chip 2 in the X direction.
Find the largest integer 7 that is close to the value divided by.

Since this 7 is a value indicating that point 1 and point 2 are separated by 7 pitches, the value obtained by dividing X ₂ −X ₁ by 7 is X
This is the shaft pitch feed amount.

As shown in FIG. 2A, ΔYn (= Y ₂ −Y ₁ ) is a value generated because the semiconductor chip 2 is mounted at a certain angle with respect to the mounting table 3. If it is 0, the Y-axis correction amount at the time of the X-axis feed is 0, but if this angle is small, every time the pitch is fed in the X-axis direction, Y ₂ −
If move the dimension only Nobutsu table 3 in the Y direction obtained by dividing Y ₁ in 7, it is possible to always align the center of the conveying tool and the center of the semiconductor chip 2.

Similarly, the largest integer 8 close to a value obtained by dividing Y ₃ −Y ₂ by the dimension Y _CH of the semiconductor chip 2 in the Y direction is obtained.

Since 8 is a value indicating that point 2 and point 3 are separated by 8 pitches, a value obtained by dividing Y ₃ −Y ₂ by 8 is the Y-axis pitch feed amount.

As shown in FIG. 2B, ΔXn (= X ₃ −X ₂ ) is a value generated because the semiconductor chip 2 is mounted at a certain angle with respect to the stage 3. If it is 0, the X-axis correction amount at the time of Y-axis feed is 0. However, if this angle is minute, X ₃ −
If moving Nobutsu stand 3 only in the X direction dimension divided by X ₂ in 8, it is possible to always align the center of the conveying tool and the center of the semiconductor chip 2.

Thus, the coordinates of three points near the reference coordinates are read, and the X-axis pitch feed amount, the Y-axis correction amount at the time of the X-axis feed, the Y-axis feed amount, the X-axis correction amount at the time of the Y-axis feed are read from these coordinates. By moving the stage 3 by the amount of correction at the time of feeding the stage 3 every time the stage 3 is pitch-fed, the center of the semiconductor chip 2 to be conveyed and the center of the transfer tool 4 are matched to be accurate. The semiconductor chip 2 can be transported by the transport tool 4.

〔The invention's effect〕

As is clear from the above description, according to the present invention, by reading the coordinates of the corners of the semiconductor chip, it is possible to calculate the feed pitch amount and the correction amount in the direction orthogonal to the feed direction extremely easily. There is no need to perform position correction on the semiconductor chip of the present invention, so that there is an advantage that a semiconductor chip with a chip size in a wide range can be efficiently and accurately picked up by a transfer tool, and it is extremely economical and reliable. It is possible to provide a semiconductor chip pickup method that can be expected to have an improved effect.

[Brief description of the drawings]

FIG. 1 is a diagram showing an embodiment according to the present invention, FIG. 2 is a diagram showing correction for a stage feed of an embodiment according to the present invention, and FIG. 3 is a diagram showing a conventional semiconductor chip pickup method. ,. In the figure, 1 is a semiconductor wafer, 2 is a semiconductor chip, 2a is an edge line (X), 2b is an edge line (Y), 3 is a mounting table, 4 is a transfer tool, 5 is a CRT display device, and 5a is an alignment. Reference line (X), 5b indicates an alignment reference line (Y).

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) H01L 21/78 H01L 21/68

Claims (1)

(57) [Claims] 1. A semiconductor chip formed on a semiconductor wafer (1) mounted on a stage (3) is transferred from the stage (3) by using a transfer tool (4). A method for picking up a semiconductor chip, wherein the transfer tool (4) and the center of the semiconductor chip coincide with each other, wherein a straight line connecting the two is formed on the work table (3). The reference coordinates A, B, and C of three points orthogonal to each other are defined, the AB direction is defined as the X axis, the BC direction is defined as the Y axis, and the coordinates (X ₁ , Y) of the corner of the semiconductor chip in the vicinity of the reference coordinate A are set. ₁ ), the coordinates (X ₂ , Y ₂ ) and (X ₃ , Y ₃ ) of the corner of the semiconductor chip near the reference coordinates B and C are read, and the coordinates (X ₁ ) of each corner of the semiconductor chip are read. ,
From Y ₁ ), (X ₂ , Y ₂ ) and (X ₃ , Y ₃ ), X axis pitch feed amount, Y axis correction amount at X axis feed, Y axis feed amount, X axis correction at Y axis feed Calculating the amount, calculating the coordinates of the center of the semiconductor chip from the coordinates of the corner of the semiconductor chip at which pickup is to be started, and the outer dimensions of the semiconductor chip, and moving the stage to move the center to the transfer tool ( When the semiconductor chip is transported so as to coincide with the center of 4) and the stage (3) is sent in the X-axis direction, the stage (3)
Each time is fed in the X-axis direction by the X-axis pitch feed amount, the semiconductor chip is moved in the Y-axis direction by the Y-axis correction amount at the time of the X-axis feed to convey an adjacent semiconductor chip, and the stage ( When sending 3), the stage (3)
Each time is fed in the Y-axis direction by the Y-axis pitch feed amount, the semiconductor chip is moved in the X-axis direction by the X-axis correction amount at the time of the Y-axis feed to convey an adjacent semiconductor chip. A semiconductor chip pick-up method, wherein the semiconductor chip is picked up by the transfer tool (4) while correcting an inclination angle between X and Y axes and an edge line of the semiconductor chip.