JP2533375B2 - Lead and bump position detection method in tape bonding - Google Patents

Description

The present invention relates to a semiconductor integrated circuit (IC) and a large-scale integrated circuit (LS).
The present invention relates to a method for detecting the positions of leads and bumps when performing tape bonding of semiconductor parts of I).

[Background Art] When manufacturing a semiconductor integrated circuit (ICF or large-scale integrated circuit (LSI), generally, a tape-side lead formed in a film shape and a bump on a chip positioned on a positioning base are formed. Need to be relatively matched, so
In the tape bonding method, the chip to be bonded is rotated in the θ direction and the X direction, the Y direction so that the leads formed on the tape side and the bumps on the chip to be bonded are relatively aligned. It has been displaced.

Then, according to the conventional method, as shown in FIG.
The positions of the lead 21 on the side and the bump 23 on the side of the chip 22 are detected separately. For this position detection, the operator makes an eye alignment with two arbitrary points ▲ A ₁ and ▲ A ₂ stored in advance on the tape 20 side while looking at a monitor (not shown), or an image processing device (not shown). ), The coordinates are calculated as coordinates on the XY table. On the other hand, on the chip 22 side that is the component to be bonded, two arbitrary points are
B1 and ▲ B2 are stored in advance. This chip 22 side is also calculated by the operator performing eye-alignment while looking at the monitor or detecting by the image processing device.

It should be noted that the coordinates of the holes 24 on the tape 20 side and the rectangular sides on the chip 22 side are stored in advance in the image processing apparatus.
Then, using the coordinates of the midpoints S and S'as a reference, the tape
Correction is performed so that the midpoint coordinates on the 20 and chip 22 sides match. However, since the tape 20 side is fixed to the positioning table, the chip 22 side is rotated by the XY table in the θ direction and is displaced in the X direction and the Y direction to be aligned.

In addition, the inspection after bonding is performed by visual inspection using a device different from the bonding device.

[Problems to be Solved by the Invention] However, in the conventional tape bonding method, a binarization circuit built in the image processing apparatus (for example, a portion of the lead LP is brightened and a portion to be read is set to "1"). The coordinates of each of the leads 21 can be obtained by a lead locator (search mechanism) (not shown) using a mechanism for reading the rest of the area darkened and digitized as "0". The detection point by this lead locator is configured to find the center of each lead.
Similarly, the center of the bump is determined from the bump image in the same image. The relative shift amount between the centers of the leads and the bumps to be bonded is calculated. This misalignment amount can be detected and corrected for each lead by converting it to the coordinates on the XY table for each lead, but when bonding with the tape bonder, the tape side and the chip side are pressed at once and bonded. It is not possible to correct the deviation amount between the leads for each lead. Moreover, in the method of separately correcting the tape side and the chip side as in the conventional method, it is not possible to perform high-precision correction when there are many variations between leads and bumps on the chip side, and sufficient bonding cannot be performed. There is a drawback that you cannot do it. In such a case, there is a drawback that it cannot be dealt with in the case where the number of pins of the lead and the bump reduction are promoted. In addition, such an amount of deviation is
It may also occur due to assembly error between stages of the XY table, chip transfer to the bonding stage, tape feed accuracy, etc.

In addition, since the inspection after bonding is performed by a visual inspection by a person using a device different from the bonding device, there is a drawback that the visual inspection process cannot be automated.

Therefore, the present invention has been made in view of the above-mentioned drawbacks of the prior art. By correcting the leads on the tape side and the bumps on the chip side at the same time, the relative positional deviation between the leads is effective even in the case of a multi-pin lead. A tape bonding lead that can be automatically inspected by detecting the relative deviation between the lead and the bump during or after bonding as well as automatically correcting within the bonding range. An object of the present invention is to provide a bump position detecting method.

[Means for Solving the Problems] The method for detecting the positions of leads and bumps for tape bonding according to the present invention selects bumps on a chip to be bonded, which are opposed to arbitrary leads picked up by a camera,
After moving the bumps in the same visual field by the XY direction and the rotation angle displacement means, the lead and the bump are binarized by the image processing device, and the lead direction is determined based on the binarized value. The determined lead width and bump width are respectively obtained, and the relative deviation amount between the lead and bump is calculated from the obtained values, and based on the data input in advance in the image processing apparatus. The amount of relative deviation between the lead and the bump is corrected and bonding is performed.

EXAMPLES Next, the present invention will be described in detail with reference to the drawings.

FIG. 1 is a diagram showing an outline of the configuration of a tape bonding apparatus according to the present invention.

In FIG. 1, a camera 1 including a camera head 1a, a lens 1b, and an illuminating lamp 1c is mounted on an XY table drive mechanism 2 that is movable in the X and Y directions. The tape 4 and the chip 5 positioned on the XYθ table drive mechanism 3 rotatable in the θ direction are imaged. The output of the camera 1 is input to the image processing device 6. The image processing device 6 includes a clock generation circuit, a horizontal and vertical synchronization signal generation circuit, a clock pulse counting circuit,
It is composed of a control circuit including a microprocessor and the like, a binarization circuit and the like. In particular, this binarization circuit has a configuration in which, for example, a portion of the lead post is lightened and the portion to be read is set to "1", and the other portion is darkened to be read as "0" and digitized. Has become. This binarized signal is input to the monitor 7 and at the same time
The control circuit in the image processing device 6 calculates the deviation amount between the lead on the tape 4 side and the bump on the chip 5 side imaged by the camera 1, and corrects the relative deviation amount between the lead and the bump. Based on this correction, the image processing device 6 sends a command to the table control unit 8 to drive and control the XY table drive mechanism 2 and the XYθ table drive mechanism 3.

 FIG. 2 is an explanatory view showing the method of the present invention.

In the figure, 5 is a chip positioned on the table positioning table of the XYθ table drive mechanism 3. 4a, 4b, 4c to 4f are leads formed on the tape side. The tip of this lead is a free end. Reference numerals 9 and 10 denote detection frames that can be processed by the image processing device 6 through the camera 1. 2B and 2C are enlarged views of the range of the detection frames 9 and 10. The chip 5 is moved in the Y direction and the X direction by the XYθ table drive mechanism 3 to obtain the bumps 5a, 5a.
The state is shown in which b, 5c are associated with the leads 4a, 4b, 4c and the bumps 5d, 5e, 5f are associated with the leads 4d, 4e, 4f, respectively.

FIG. 2B shows a state in which the leads 4b on the tape side and the centers of the bumps 5b on the chip 5 side are deviated by Δx in the X direction.
Fig. 2 (c) shows tape-side leads 4e and chip-side bumps.
It shows a state in which the center of 5e is deviated in the Y direction by Δy. The deviations shown in FIGS. 2 (b) and 2 (c) are such that the lead and the chip are pressed together at the same time in tape bonding, so that even if one lead completely matches the bump, This is because there is a possibility that there is a deviation of Δx or Δy.

Therefore, the present invention provides, as a method for correcting the amount of deviation,
First, as shown in FIG. 3, in a state in which arbitrary leads and bumps are aligned with each other, the binarization circuit in the image processing device 6 binarizes the leads 4n and the bumps 5n to obtain the direction of the leads 4n. . The leads 4n and the bumps 5n are normally formed with a width smaller than the bump shape, whereas the longitudinal direction of the leads is formed longer than the width of the bump shape. Therefore, if scanning is performed in the X and Y directions. , These directionality can be determined.

Next, as shown in FIG. 3 and FIG. 3, each of the bumps 5n and the leads 4n is image-scanned by the camera 1 to find the center of each of the bumps 5n and the leads 4n in the width direction. As a result, the image processing device 6 obtains the amount of deviation between the bump 5n and the lead 4n based on the data previously input into the image processing device 6. In this way, the leads and the bumps are raised in the same visual field, and the deviation amounts Δx and Δy between the centers of the leads and the bumps are detected at the same time. Then, the shift amount is calculated between the leads to obtain the relative shift amount between the lead and the bump, and the data corresponding to each lead is stored as data in the storage circuit in the image processing apparatus 6. This shift amount calculation need not be performed for all leads, and any lead may be selected as appropriate.

Next, the control circuit in the image processing device 6 averages the data based on the stored data of the shift amount obtained in the image processing device 6. Based on this averaged average value, the amount of deviation from the previously input regular bonding point coordinates is calculated, the XY table is driven, and X is driven.
And the chip is moved in the Y direction for correction. After this correction is completed, bonding is performed.

By performing the correction as described above, the deviation amount of the center between the lead and the bump is included in the average error. Therefore, even if the centers of the bumps on the tape side, the leads, and the chip side are deviated, they are relatively pressure-bonded within the effective bonding surface.

Even if the relative displacement amount averaged by the above method is corrected, since the tip of the lead is a free end, the lead is bent in a direction orthogonal to the longitudinal direction of the lead, so that the bonding is not performed as a result. May occur.

In view of this, the present invention warns that there is a bonding failure by providing a limit value for the amount of deviation during detection. To set the limit value, the width of the lead and the size of the chip may be input in advance as data. In this case, it is preferable that the lead and the chip are not completely aligned with each other and that the lead is bent and set in consideration. The warning method may be any means such as displaying on the monitor 7 that the bonding is defective or issuing a warning sound. When this warning is issued, a processing program for automatically stopping the bonding work can be set.

Further, if the deviation amounts of the four sides of the chip are corrected, the deviation amounts of not only the X and Y directions but also the θ direction can be corrected.

The present invention can be applied not only before bonding but also after or during bonding.

That is, after the representative points of the tape are aligned, the amount of deviation between the lead and the bump is obtained by the method shown in FIG. 3, and it is inspected whether this amount of deviation is within a preset range.

As described above, according to the present invention, the leads on the tape side and the bumps on the chip side are simultaneously corrected, so that even if there is a relative positional deviation between the leads, the correction is made within the effective bonding range. Then, there is an effect that the bonding can be automatically performed. In addition, the position inspection after bonding is automated and the inspection standard is clarified, which has the effect of improving the reliability of the final product.

[Brief description of drawings]

FIG. 1 is an embodiment of the present invention. A schematic view of an apparatus according to the present invention, FIGS. 2 and 3 are explanatory views showing a method of the present invention, and FIG. 4 shows a conventional tape bonding method. It is a figure. 1 ... Camera, 1a ... Camera head, 1b ... Lens, 1c
...... Illumination lamp, 2 ... XY table drive mechanism, 3 ... XYθ table drive mechanism, 4 ... Tape, 4a, 4b, 4c, 4d, 4e, 4f ...
... lead, 5 ... chip, 5a, 5b, 5c, 5d, 5e, 5f ... bump, 6 ... image processing device, 7 ... monitor, 8 ... table control unit, 9,10 ... detection frame, 20 …… tape, 21 …… lead, 22 …… chip, 23 …… bump, 24 …… hole.

Claims (3)

(57) [Claims] 1. A lead formed on a tape is placed on a positioning table, and a chip placed on a table is relatively displaced to relatively align the lead and the bump on the chip. In the bonding tape bonding method, select a bump on the chip to be bonded, which corresponds to any lead imaged by the camera, and select this bump.
After moving within the same visual field by the XY direction and the rotation angle displacement means, the lead and the bump are binarized by the image processing device, and the lead direction is determined based on the binarized value.
The width of the lead and the width of the bump which were judged respectively were calculated,
The relative deviation amount between the lead and the bump is calculated from the obtained value, and the relative deviation amount between the lead and the bump is corrected based on the data previously input in the image processing apparatus to perform bonding. A method for detecting the positions of leads and bumps for tape bonding, which is characterized in that 2. An amount of deviation calculated between a plurality of leads and bumps is calculated and calculated in an image processing apparatus to set an average value, and the set value is stored in a storage means in the image processing apparatus. 2. The method according to claim 1, wherein whether or not the stored relative displacement amount between the lead and the bump is within a predetermined value set in advance is determined during or after bonding. Tape bonding lead and bump position detection method. 3. The average value is a value obtained by calculating relative displacement amounts between a plurality of leads and bumps and averaging the displacement amounts. Of tape bonding lead and bump position detection.