JP2844409B2 - Semiconductor positioning method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement in a semiconductor positioning method in a chip bonding apparatus for bonding a semiconductor chip to a mounting object such as a substrate or a lead frame.

[0002]

2. Description of the Related Art A conventional flip chip bonding apparatus requires a process of positioning a semiconductor chip with respect to a substrate. In this semiconductor positioning method, the wiring pattern or the recognition mark of the semiconductor chip is read by one recognition camera, and the wiring pattern or the recognition mark of the substrate is read by the other recognition camera, and both of the read both are subjected to image processing. Then, based on the result, the semiconductor chip and / or the substrate are moved to perform the alignment.

[0003]

However, when such a semiconductor positioning method is used, the thermal expansion of the mounting member of the recognition camera, the thermal expansion of the ball screw used as the moving means, and the servo motor used as the moving means. Due to the limitation of the driving resolution, the magnification of the recognition camera and the limitation of the resolution, etc., high-precision position accuracy could not be obtained, and the accuracy of ± 5 μm was the limit with the current technology.

Assuming that the accuracy of the positioning of the semiconductor chip is ± 5 μm, the dimension between the adjacent semiconductor chips can be guaranteed only with the sum of the errors of the two, that is, the accuracy of ± 10 μm. However, with the recent technological innovation, a demand has arisen to reduce the dimension between adjacent semiconductor chips to ± 5 μm or less. SUMMARY OF THE INVENTION The present invention provides a semiconductor positioning method that meets the above-mentioned needs and can ensure an accuracy of ± 5 μm or less.

[0005]

According to the present invention, there is provided a semiconductor positioning method in a chip bonding apparatus for bonding a semiconductor chip to a substrate or the like. In the process, a predetermined value at which the semiconductor chip is separated from the positioning reference is added to the value of the detection result, and the semiconductor chip and the positioning object are relatively moved to the position of the value obtained as a result, thereby temporarily. It is an object of the present invention to provide a semiconductor positioning method characterized by performing positioning, observing the provisionally positioned semiconductor chip and a positioning object with one high-magnification recognition camera, and correcting the relative positions of the two.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The embodiment shown in the drawings will be described below. FIG. 1 is a view showing one embodiment of a semiconductor positioning device in a bonding device used in the present invention, wherein 1 is a positioning device, and 2 is a bonding tool in the bonding device. The bonding tool 2 is movable in an X-axis (horizontal direction in the figure), a Y-axis (front-back direction in the figure), and a Z-axis direction (vertical direction) by a driving mechanism (not shown). Note that the semiconductor chip 3 is adsorbed to the tip of the bonding tool 2. As explained later,
This semiconductor chip 3 is the second semiconductor chip to be bonded.

In the figure, reference numeral 4 denotes a base, and 5 denotes an X table movable on the base 4 in the X-axis direction (left-right direction in the figure), which is controlled by a ball screw 7 driven to rotate by a motor 6. It is configured to be movable. Reference numeral 8 in the drawing denotes a Y movable on the X table 5 in the Y-axis direction (front-back direction in the drawing).
This is a table, which can be moved by a motor 9 by the same means as the X table 5.

Provided on the Y table 8 is a fine movement table 10 on which a substrate 12 is mounted. The central portion of fine movement table 10 is made of transparent glass 13. The size of the transparent glass 13 is wider than the range in which the semiconductor chips on the substrate 12 placed on the fine movement table 10 are joined. The fine movement table 10 can be finely moved by a piezo actuator 11.

Although the driving force of the fine movement table 10 in the embodiment utilizes the piezo actuator 11, it is also possible to use a ball screw, a differential screw or a cam mechanism having an extremely small lead pitch. The first semiconductor chip 14 bonded is present on the substrate 12 in the illustrated embodiment.

Reference numeral 15 denotes a first recognition camera for recognizing the position of the semiconductor chip 3, reference numeral 16 denotes a second recognition camera for recognizing the position of the substrate 12, and reference numeral 17 denotes a portion near the junction between the semiconductor chip and the substrate 12. The high-power recognition camera provided in
This is for measuring the interval between the semiconductor chip 3 and a specific pattern.

Next, a semiconductor positioning method according to an embodiment will be described. First, in the embodiment, the substrate 12 is formed by an ordinary method.
Is bonded to the first semiconductor chip 14. That is, the position of the semiconductor chip is recognized by the first recognition camera 15, and the substrate 1 is recognized by the second recognition camera 16.
2 and the first semiconductor chip 14 is bonded to a position based on the calculation.

For the second and subsequent semiconductor chips 3, first, the recognition marks of the semiconductor chip 3 are observed by the first recognition camera 15, and the recognition marks of the substrate 12 are observed by the second recognition camera 16, as in the conventional case. The bonding position is calculated by image processing of both. Thereafter, the bonding tool 2 is moved so that the X-axis and Y-axis positions of the bonding tool 2 of the bonding apparatus reach the positions obtained by the calculation.

Next, the bonding tool 2 is moved in a direction away from the adjacent first semiconductor chip 14 by 20 μm. The dimension at this time, that is, a predetermined value at which the semiconductor chip 3 is separated from the positioning reference, is determined by the positioning accuracy using the recognition cameras 15 and 16.
Double the value. Recognition cameras 15 and 16 in the embodiment
Is ± 10 μm. In the embodiment, the bonding tool 2 is moved by 20 μm after moving to the X-axis and Y-axis positions calculated, but in another embodiment, the dimension of 20 μm away from the calculated position is set. Alternatively, the bonding tool 2 may be directly moved to the position of each axis of the value.

Thereafter, the X and Y axes of the bonding tool 2 are fixed, and the bonding tool 2 is lowered. The bonding tool 2
Z having a gap of several μm between the substrate 12 and the semiconductor chip 3
Stop at axis position.

In the above-described embodiment, the temporary positioning is performed by moving the bonding tool 2 in the X-axis direction and the Y-axis direction.
Has a driving mechanism in the X-axis direction and the Y-axis direction called an X table 5 and a Y table 8, so that the movement by the X table 5 and the Y table 8 The movement of the temporary positioning can also be performed by the movement of both the drive mechanism 2 and the drive mechanism of the semiconductor positioning device.

After the tentative positioning, the second semiconductor chip 3 to be bonded to the recognition mark of the adjacent first semiconductor chip 14 by the third camera 17 of high magnification.
The substrate 12 is moved by moving the fine movement table 10 so that the dimension between the two recognition marks becomes a predetermined dimension while observing the recognition mark.

At this time, since the dimensions of the second semiconductor chip 3 to be bonded to the adjacent first semiconductor chip 14 from the third recognition camera 17 are different, the focal points of the third recognition camera alternately. It is designed to match the partner semiconductor chip. After such positioning, the second semiconductor chip 3 is bonded to the substrate 12.

[0019]

According to the present invention, when a semiconductor chip 3 is bonded to a mounting object such as a substrate 12, a conventional method is performed, and a predetermined value at which the semiconductor chip 3 is separated from a positioning reference is added. The semiconductor chip 3 and the object to be mounted are moved to the position of the value obtained as a result to perform temporary positioning, and the semiconductor chip and the object to be mounted that are temporarily positioned are observed with one high-magnification recognition camera. Since the relative position is corrected, it is possible to perform the bonding corresponding to the adjacent pitch with high accuracy.

The effect of the embodiment is as follows. In the correction movement after the provisional positioning, the fine movement table 10 is used separately from the X-axis and Y-axis movement means of the bonding tool 2 and the semiconductor positioning apparatus 1 itself. It is possible to perform a semiconductor positioning method that can cope with adjacent pitches with high accuracy in a short time.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing one embodiment of a semiconductor positioning device used in the present invention.

[Explanation of symbols]

 1. . . . . Positioning device 2. . . . . Bonding tool 3,14. . Semiconductor chip 4. . . . . Base 5. . . . . X table 6,9. . . Motor 7. . . . . Ball screw 8. . . . . Y table 10. . . . . Fine movement table 11. . . . . Piezo actuator 12. . . . . Substrate 13. . . . . Glass 15. . . . . First recognition camera 16. . . . . Second recognition camera 17. . . . . Third recognition camera

Claims (1)

(57) [Claims] A semiconductor positioning method in a chip bonding apparatus for bonding a semiconductor chip to a substrate or the like, wherein a relative position between the semiconductor chip and a positioning target is detected by image processing, and a value of the detection result is used as a positioning reference. A predetermined value at which the semiconductor chip is separated from the predetermined position is added, and the semiconductor chip and the positioning object are relatively moved to the position of the resulting value to perform temporary positioning, and the temporarily positioned semiconductor chip and the positioning object are positioned. A semiconductor positioning method comprising: correcting a relative position between two images by observing the images with one high-magnification recognition camera.