JPH036842A - Detection of position of lead and bump in tape bonding - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is applicable to semiconductor integrated circuits (IC) and large-scale integrated circuits (L
This invention relates to a method for detecting the positions of leads and bumps when performing tape bonding of semiconductor components (SI).

[Background Art] When manufacturing semiconductor integrated circuits (ICs) and large-scale integrated circuits (LSIs), leads on the tape side that are optically formed into a film and bumps on the chip positioned on a positioning stand are used. It is necessary to make them relatively consistent. Therefore, in the chip bonding method, the chip to be bonded is rotated in the θ direction and direction, and the Y direction.

In the conventional method, as shown in FIG.
The positions of the leads 21 on the side and the bumps 23 on the chip 22 side are detected separately. This position detection is performed using any two points A3. The coordinates on the XY table are calculated by an operator aligning the coordinates A2 while looking at a monitor (not shown), or by detecting the coordinates using an image processing device (not shown). On the other hand, there are also two arbitrary points B1. B2 is stored in advance.

The chip 22 side is also calculated by the operator's eye alignment while looking at the monitor, or by detection by an image processing device.

Note that the coordinates of each side of the hole 24 on the tape 2o side and the square shape on the chip 22 side are stored in advance in the image processing device. Then, correction is made to match the coordinates of the midpoints on the tape 20 and chip 22 sides with reference to the coordinates of the midpoints S and So. However, since the tape 2o side is fixed to the positioning table, the chip 22 side is
rotation in the direction and displacement in the X and Y directions to match.

Further, post-bonding inspection 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, the binarization circuit built in the image processing device (for example, the lead LP part is brightened and the read part is set to "1"). The coordinates of each lead 21 can be determined using a lead locator (search mechanism) (not shown) using a digital reading mechanism (rOJ) with the other parts darkened and digitized. 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 within the same image. The relative deviation between the centers of the leads and bumps to be bonded is calculated. This amount of deviation can be corrected by converting it into coordinates on the XY table for each lead and detecting it for each lead. However, when bonding with a tape bonder, the tape side and chip side are bonded by pressing at the same time. It is not possible to correct the amount of deviation between individual leads. Moreover, with the conventional method of correcting the tape side and the chip side separately, if there are large variations between each lead and variations in the bumps on the chip side, it is not possible to perform highly accurate correction, resulting in insufficient bonding. The disadvantage is that it cannot be done. In such a case, there is a drawback that it is not possible to cope with the trend of increasing the number of lead bins and making the bumps smaller. In addition, in fully automatic bonding, such a deviation may also occur due to assembly errors between the XY child table stages, chip transfer to the bonding stage, tape feeding accuracy, etc.

In addition, post-bonding inspections are performed visually by humans using equipment separate from the bonding equipment.
There is a drawback that this visual inspection process cannot be automated.

Therefore, the present invention was developed in view of the above-mentioned drawbacks of the conventional technology, and by simultaneously correcting the leads on the tape side and the bumps on the chip side, it is possible to effectively correct the relative positional deviation between each lead even in the case of multi-bin reads. A tape bonding lead that automatically performs bonding by correcting it within the bonding range, and also automatically performs bonding inspection by detecting the relative deviation between the lead and bump during or after bonding. The present invention aims to provide a bump position detection method.

[Means for Solving the Problems] The tape bonding lead and bump position detection method of the present invention selects a bump on a chip that is to be bonded relative to an arbitrary lead imaged by a camera, and After moving within the same field of view using the XY direction and rotational angle displacement means, the lead and bump are each binarized by an image processing device, and the lead direction is determined based on the binarized values. The width of the lead and the width of the bump are respectively determined, and the relative deviation between the lead and the bump is calculated from the determined values and corrected based on the data input into the image processing device in advance. It is designed to be bonded.

[Example 1 Next, the present invention will be explained in detail using the drawings.

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

In FIG. 1, a camera 1 consisting of a camera head la, a lens 1b, and an illumination lamp IC is mounted on an XY table drive mechanism 2 that is movable in the X and Y directions. The tape 4 and chip 5 positioned on the XYθ table drive mechanism 3 rotatable in the θ direction are imaged. The output of this camera 1 is input to an image processing device 6. The image processing bag @6 is composed of a clock generation circuit, a horizontal and vertical synchronization signal generation circuit, a clock pulse counting circuit, a control circuit including a microprocessor, a binarization circuit, and the like. In particular, this binarization circuit has a structure in which, for example, the read post part is brightened and read as "1", and other parts are darkened and digitized as "0". It becomes. At the same time that this binary signal is input to the monitor 7, the control circuit in the image processing device 6 calculates the amount of deviation between the lead on the tape 4 side imaged by the camera l and the bump on the chip 5 side. to correct. Based on this correction, the image processing device 6 sends a command to the table control unit 8 to control the XY table drive machine lateral 2 and the XYθ table drive machine lateral movement.

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

In the figure, 5 is a chip positioned on the table positioning base 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. 9 and 10 are detection frames that can be processed by the image processing device 6 through the camera 1. FIGS. 2(b) and 2(c) are enlarged views of the detection frames 9 and 10, in which the chip 5 is moved in the Y direction and the X direction by the XYθ table drive mechanism 3, and bumps 5a, 5b, 5c Lead 4a, 4b, 4
Bump 5d corresponds to c.

A state in which leads 5e and 5f correspond to leads 4d, 4e, and 4f, respectively, is shown.

FIG. 2(b) shows a state in which the tape side glue 4b and the center of the bump 5b on the chip 5 side are shifted by ΔX in the X direction, and FIG. 2(C) shows the tape side glue 4e and A state in which the center of the bump 5e on the chip side is shifted by Δy in the Y direction is shown. The misalignment shown in Figures 2(b) and (C) is due to the fact that in tape bonding, the leads and chip are crimped at the same time, so even if one lead is perfectly aligned with the bump, other leads may This is because a situation where there is a deviation in ΔX or Δy occurs.

Therefore, in the present invention, as a method for correcting this amount of deviation, first, as shown in FIG. 4n and the bump 5n are binarized to determine the direction of the lead 4n. The lead width of the lead 4n and the bump 5n is usually smaller than the bump shape, but the long direction of the lead is longer than the width of the bump shape, so it is difficult to scan in the X and Y directions. For example, these directions can be determined.

Next, as shown in FIG.
Find the center in the width direction of each lead 4n and lead 4n. Thereby, the image processing device 6 calculates the amount of deviation between the bump 5n and the lead 4n based on the data inputted into the image processing device 6 in advance. In this way, the leads and bumps are placed in the same field of view, and the deviation amounts △X and △ between the centers of the leads and bumps are determined.
y is detected at the same time. Then, by calculating the amount of deviation between each lead, the relative amount of deviation between the lead and the bump is determined, and the data corresponding to each lead is stored as data in the storage circuit within the image processing device 6. This deviation amount calculation does not need to be performed for all leads, and may be performed by selecting any lead as appropriate.

Next, based on the data stored in the image processing device 6, a control circuit in the image processing device 6 averages the data.

Based on this averaged data, the amount of deviation from the regular bonding point coordinates input in advance is calculated and
The table is driven to move the chip in the X and Y directions for correction. After completing this correction, bonding is performed.

By performing the above correction, the amount of deviation between the centers of the leads and bumps is included within the average error. Therefore, even if there is a misalignment between the centers of the leads on the tape side and the bumps on the chip side, they will be relatively pressed together within the effective bonding surface.

Even if the averaged relative deviation amount is corrected using the above method, the tip of the lead is a free end, so if the lead is bent in a direction perpendicular to the longitudinal direction of the lead, etc., bonding is not possible as a result. may occur.

Therefore, the present invention provides a limit value for the amount of deviation at the time of detection so as to warn that there is a bonding defect. This limit value can be set by inputting the lead width and chip size in advance as data.

In this case, it is preferable to take into consideration the bending of the leads, etc., rather than setting the leads and the chip so that they do not completely match. The warning may be given by any means such as displaying the defective bonding on the monitor 7 or emitting a warning sound. It is also possible to create a processing program that automatically stops the bonding operation when this warning occurs.

Furthermore, if the amount of deviation on the four sides of the chip is corrected, it is possible to correct the amount of deviation not only in the X and Y directions but also in the θ direction.

Next, the present invention can be applied not only before bonding but also after or during bonding.

That is, after aligning the representative points of the tape, the amount of deviation between the lead and the bump is determined by the method shown in Figure 3, and it is determined whether this amount of deviation is within a preset range (including the average value and limit value). inspect.

[Effects of the Invention] As explained above, according to the present invention, the leads on the tape side and the bumps on the chip side are corrected at the same time, so even if there is a relative positional deviation between each lead, it can be corrected within the effective bonding range. This has the advantage that bonding can be performed automatically.

In addition, position inspection after bonding is automated, inspection standards are clarified, and the reliability of the final product is improved.

[Brief explanation of the drawing]

FIG. 1 shows an embodiment of the present invention, and is a schematic diagram of an apparatus according to the present invention, FIGS. 2 and 3 are explanatory diagrams showing the method of the present invention, and FIG. 4 shows a conventional tape bonding method. It is a diagram. 1...Camera, 1a...Camera head, 1b...
Lens, IC...Lighting light, 2...XY child table movement 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)

[Claims] (1) After placing the leads formed on the tape on a positioning table and relatively displacing the chip placed on the table so that the leads and bumps on the chip are relatively aligned, bonding is performed. In the tape bonding method, a bump on a chip to be bonded that is opposite to an arbitrary lead imaged by a camera is selected, and after moving this bump within the same field of view by an XY direction and rotational angle displacement means, image processing is performed. The device converts the leads and bumps into binarized values, determines the direction of the leads based on the binarized values, determines the determined widths of the leads and bumps, and calculates the determined values. The positions of the leads and bumps in tape bonding are characterized in that the relative deviation amount between the leads and bumps is calculated and bonding is performed after correction based on data inputted in advance into an image processing device. Detection method. (2) Calculate the amount of deviation calculated for the plurality of leads and bumps, calculate it within the image processing device, set a predetermined value, and store this set value in a storage means within the image processing device. 2. The tape bonding lead according to claim 1, wherein it is determined at the time of bonding or after bonding whether the relative deviation amount between the lead and the bump is within the stored predetermined value. Bump position detection method. (3) The tape bonding lead and bump position detection method according to claim 2, wherein the predetermined value is an average value or a limit value.