WO2002043133A1

WO2002043133A1 - Alignment method for chip mounter

Info

Publication number: WO2002043133A1
Application number: PCT/JP2000/008199
Authority: WO
Inventors: Akira Yamauchi; Yoshiyuki Arai
Original assignee: Toray Engineering Co., Ltd.
Priority date: 1999-03-15
Filing date: 2000-11-21
Publication date: 2002-05-30
Also published as: JP2001217596A

Abstract

A method for precise alignment while in a short tact time by a small number of alignments for a chip mounter is disclosed. A recognition mark (11) made on a chip (12) held by a head (1) and a recognition mark (6) made on a substrate (5) supported by a substrate supporting stage (2) are recognized by a recognition means (3) having two visual fields, and the positional difference between both of the recognition marks (6, 11) is corrected to lie within a range of target accuracy by parallel movement control and rotation control of a rotatable table (4). To reduce the error in rotation method within a specified range, at least the rotation control is first performed, and after the control, the parallel movement control alone is performed.

Description

Description Alignment method for chip mounting equipment

The present invention relates to an alignment method in a chip mounting apparatus for mounting a chip on a substrate. Background art

Conventionally, as is well known, chip mounting is performed by precisely positioning a chip held by a head and a mounting position of a substrate supported by a substrate holding stage arranged below the chip. Lower the head when mounting.

Therefore, prior to such mounting, in a state where the substrate holding stage is moved to the alignment execution position, that is, in a state in which the chip and the substrate are roughly positioned, for example, a predetermined position provided on the chip and the substrate is provided. Recognition marks are recognized by two field of view recognition means, and the precise positioning of the chip and the substrate is controlled by controlling the driving of the substrate holding stage so that the amount of displacement between the two recognition marks is within the target accuracy range. Is going.

In this case, in such a state where the coarse deviation is determined, since the positional deviation amount of both recognition marks is large, in one alignment, the positional deviation amount is set within the target accuracy range. It is difficult.

Therefore, multiple alignments are inevitable, and at this time, the movable table on which the substrate holding stage is mounted, the movable table on which the head is mounted, or both movable tables are driven. ,. Move in X-axis direction, Y-axis direction or XY-axis direction (hereinafter, simply referred to as “parallel movement”) At the same time, the rotation is performed at a predetermined angle, and the alignment is performed, that is, the translation and the rotation are performed almost simultaneously in parallel (hereinafter, simply referred to as “parallel”).

However, according to the alignment in which the parallel movement and the rotation are performed in parallel, even if the translation error is within the set range due to the previous alignment, when the rotation control is performed next, the rotation axis center is changed. Because of the occurrence of a run-out (run-out of the 0-axis), the above-mentioned translation error falls outside the target accuracy range again, and it is impossible to obtain an accuracy less than the run-out error of the axis. I was In addition, the number of times the alignment is repeated to achieve the target accuracy is gradually increased, which has the disadvantage of increasing the tact time.

An object of the present invention is to provide an alignment method in a chip mounting apparatus capable of performing high-precision alignment in a short time in view of such a drawback. Disclosure of the invention

The inventors of the present invention have conducted intensive studies in order to solve the conventional disadvantages.First, after completing the control for setting the rotation error within the set range, the present inventors have performed only the parallel movement control without performing the rotation control. As a result, the present inventors have found that a decrease in alignment accuracy does not occur, and have arrived at the present invention.

That is, one of the alignment methods in the chip mounting apparatus according to the present invention includes a recognition mark provided on a chip held by the head and a substrate holding stage arranged below the head. The head and the substrate holding unit are configured to recognize the recognition mark provided on the supporting substrate by the recognition unit, and to correct the positional deviation amount of the two recognition marks so as to be within the target accuracy range. An array in a chip mounting device configured to be able to perform parallel movement control and rotation control of only one of the stages In the mounting method, first, at least the rotation control is performed so that the rotation direction error between the two recognition marks is within a set range, and then, after the completion thereof, only the parallel movement control is performed. I do.

According to the present invention, the chip mounting apparatus is configured to be capable of controlling the parallel movement and rotation of the head, but it is difficult for the substrate holding stage, or conversely, the parallel movement of the substrate holding stage. In a chip mounting device that is configured to perform control and rotation control, but it is difficult for the head to perform the rotation control, first, at least the rotation control is performed so that the rotation direction error is within a set range. Then, after the completion, the alignment is performed by performing only the parallel movement control, so that the error caused by the deflection of the rotation axis does not occur during the parallel movement control, and the high-precision adjustment is performed. This makes it possible to perform the counting in a short time (that is, to reduce the number of times the alignment is repeated, thereby reducing the tact time of the apparatus).

Further, another one of the alignment methods in the chip mounting apparatus according to the present invention is a recognition mark provided on a chip held by the head and a board disposed below the head. The recognition head and the recognition mark provided on the substrate supported by the holding stage are recognized by the recognition unit, and the head and the head are corrected so that the positional deviation amount of both the recognition marks is corrected to be within the target accuracy range. In an alignment method for a chip mounting apparatus configured to be able to perform both parallel movement control and rotation control of the substrate holding stage, the rotation direction error of the two recognition marks may be set within a set range. First, at least the rotation control is performed, and then, after the rotation control is completed, only the parallel movement control is performed.

According to the present invention, in a chip mounting apparatus configured to perform parallel movement control and rotation control of both a head and a substrate holding stage, first, a rotation direction error is set within a set range. At least the rotation The control is performed, and then, after the completion of the control, the alignment is performed by performing only the parallel movement control. Therefore, the error caused by the deflection of the rotation axis does not occur during the parallel movement control. Thus, high-precision alignment can be performed in a short time (that is, the number of times the alignment is repeated is reduced to reduce the tact time of the device).

In the latter invention, there are the following embodiments of the alignment.

For example, the rotation control and translation control of the head and the rotation control and translation control of the substrate holding stage are performed to perform alignment, or the rotation control of both the head and the substrate holding stage is performed. At the same time, the parallel movement control of either the head or the substrate holding stage is performed to perform the alignment, or the rotation control of either the head or the substrate holding stage is performed. Alignment is performed by performing translation control of both the head and the substrate holding stage, or rotation control and translation control of only one of the head and the substrate holding stage are performed. Or rotation control of one of the head and the substrate holding stage (for example, the head). Other plate holding stage (for example, it is possible to Arai e n t performs translation control of the substrate holding stage>. BRIEF DESCRIPTION OF DRAWINGS

Fig. 1 shows the recognition mark provided on the chip held by the head and the recognition mark provided on the substrate supported by the substrate holding stage, which are recognized by a two-field recognition means. It is a perspective view showing a figure.

FIG. 2 is an enlarged perspective view of a tool part of the head. BEST MODE FOR CARRYING OUT THE INVENTION

FIG. 1 shows a chip mounting apparatus. This mounting apparatus includes an upper head 1, a lower substrate holding stage 2, and a two-view recognition means 3 that can move between the head 1 and the substrate holding stage 2. The substrate holding stage 2 is mounted on a movable table 4 (hereinafter, this movable table is referred to as a stage-side movable table) capable of controlling translation and rotation.

The movable table 4 on the stage side includes a translation table 4b and a rotary table 4a mounted on the translation table 4b. The substrate holding stage 2 is mounted on the rotary table 4a.

Therefore, the substrate holding stage 2 can be translated in the X and Y directions in a horizontal plane by driving control of the movable table 4, and can be rotated around a vertical axis (Z direction) (0 direction). Further, a substrate 5 provided with a pair of recognition marks 6 is held at a predetermined position of the substrate holding stage 2 by vacuum suction.

On the other hand, the head 1 is a force mounted on the lifting table 8. The lifting table 8 is driven by a servo motor 13 mounted on the upper frame 7 to control a pair of mounted on the upper frame 7. It is mounted so that it can move in the Z-axis direction (vertical direction) and move up and down.

The upper end of the upper frame 7 is connected to a movable table (hereinafter, referred to as “X”, “X” direction) and rotation (“0” direction) control mounted on the upper device frame (not shown). This movable table is called the movable table on the head side.)

The movable table on the head (not shown) is Similarly to the movable table 4 on the side, it is composed of a translation table and a rotary table, and the translation table located on the upper side is attached to the above-mentioned apparatus frame while the translation table is mounted on the apparatus frame. The upper end of upper frame 7 is mounted on the rotary table located on the side.

The head 1 is composed of a block 9 mounted on the lifting table S and a tool 10 mounted on the lower end of the block 9. Tool 10 is

—A chip 12 with a built-in evening (not shown) and a pair of recognition marks 11 as shown in FIG. 2 is held by vacuum suction.

The pitch between the pair of recognition marks 6 provided on the substrate 5 and that of the chip 11 are provided at the same pitch (L). The pitch (L) of these recognition marks 6 or 11 is set to a size that fits within each field of the two-field recognition means 3.

The two-view recognition means 3 is mounted on a translation table 15a of a movable table 15 capable of translation control and elevation control. The movable table 15 is configured by attaching a parallel movement table 15a to a lifting table (not shown).

Therefore, the two-field-of-view recognition means 3 can be moved from the retracted position to a position below the head 1 by the drive control of the movable table 15 and, conversely, moved from the retracted position to the retracted position. Can be done. At this time, the height of the recognition means 3 for the two visual fields is adjusted to a predetermined height by controlling the elevation of the movable table 15. Therefore, according to this mounting apparatus, a pair of recognition marks 11 provided on the chip 12 held by the head 1 by suction and the board 5 provided by the board holding stage 2 by suction are provided. The two recognition marks 6 are recognized by the two visual field recognition means 3 and can be aligned as follows. First, the movable table 15 is driven to move the two-view recognition means 3 from the retracted position between the head 1 and the substrate holding stage 2, and the two-view recognition means 3 uses the two recognition marks 6, 1. Attempt to recognize (image) 1. At this time, if the head 1 and the substrate holding stage 2 are moved to a position where it is difficult to recognize all the upper and lower recognition marks 6 and 11, the movable side of the head (not shown) Alignment execution position by controlling the translation and / or rotation of the table and the movable table 4 on the stage or stage side, that is, recognizing all of the upper and lower parts within the visual field range of the two visual field recognizing means 3. Position marks 6 and 1 1.

The recognition of the recognition marks 6 and 11 by the two-view recognition means 3 can be performed by simultaneously recognizing all the recognition marks 6 and 11 or by recognizing the pair of recognition marks 6 provided on the substrate 5 and the chip 1 2 May be any of the individual recognition that separately performs the recognition of the pair of recognition marks 11 provided in. Note that, in this state, the substrate 5 on the substrate holding stage 2 is only roughly positioned with respect to the chip 12 held by the head 1 by suction. Then, the drive control of the movable table 4 on the stage side is performed so as to correct the position of the two recognition marks 6 and 11 based on the amount of misalignment and to make the correction as close as possible to the target accuracy range. Is performed.

In this way, drive control is performed so as to be as close as possible to the target range because the positional deviation between the two recognition marks 6 and 11 is large. This is because it is difficult to keep it within the range. In this first alignment, the translation control and the rotation control are performed in parallel.

Subsequently, a second alignment is performed through the same process as described above, and this alignment also causes the amount of displacement between the two recognition marks 6 and 11 to fall within the target accuracy range. If it is not possible, Then, the following alignments are performed one after another. At this time, if the rotation error in the previous alignment is within the set range, only the translation control is performed without performing the rotation control.

In other words, if rotation control is performed, accuracy will not be obtained due to the runout of the rotation axis. The setting range of the above rotation error is determined, for example, as follows. For example, regarding the movable table 4, the repetition accuracy of the translation table 4b is ± 1 β m, the resolution of the rotary table 4a is 13.600 degrees, and the runout error of the rotary axis is 5 rn. The pitch L of the recognition marks 6 and 11 is 10 mm and the target accuracy is ± 2. In this case, within ± 1.5 m which is the value obtained by subtracting the repetition accuracy ± l ^ m of the translation table from the target accuracy ± 2.5 / xm, that is, the pitch L of the recognition mark is 10 mm and the deviation is The angle (ø) at 1.5 m is the rotation error setting range. When the rotation error in the previous alignment is within the set range, it is considered that the rotation control has been completed, and only the parallel movement control may be performed in the next alignment.

Therefore, the alignment can be performed without being affected by the run-out error of the rotary axis of the movable table 4 on the stage side (run-out error of the 0-axis center), and the number of repeats of the alignment can be reduced. As a result, the tact time can be shortened, and the alignment can be performed with high accuracy. The recognition means 3 is moved from the position where the recognition marks 6 and 11 are recognized to the retracted position.

As described above, the example of performing the alignment by performing the rotation control and the parallel movement control of only the substrate holding stage 2 has been described. However, the alignment method is not limited thereto. That is, instead of this, the rotation control and the parallel movement control of only the head 1 may be performed to perform the same alignment. In addition to controlling rotation of one of the head 1 and the substrate holding stage 2 (for example, the head 1), the other of the head 1 and the substrate holding stage 2 (for example, the substrate holding stage 2) It is also possible to perform the parallel movement control described above and perform the same alignment.

In addition, the rotation control and the parallel movement control of both the head 1 and the substrate holding stage 2 may be performed to perform the same alignment.

In addition, the rotation control of both the head 1 and the substrate holding stage 2 is performed, and the parallel movement control of one of the head 1 and the substrate holding stage 2 is performed. May be included.

In addition, while controlling the rotation of one of the head 1 and the substrate holding stage 2, the parallel movement control of both the head 1 and the substrate holding stage 2 is performed and the alignment is similarly performed. Is also good.

In this way, various aspects can be aligned. This is because the above-described chip mounting apparatus is configured to perform the parallel movement control and the rotation control of both the head 1 and the substrate holding stage 2. · That is, as described above, the head 1 is mounted on the movable table (the movable table on the head side) capable of controlling the parallel movement and the rotation, and the substrate holding stage 2 is controlled by the parallel movement and the rotation. This is because it is mounted on a movable table that can be controlled (the movable table 4 on the stage side). In the above-described embodiment, the parallel movement control and the rotation control are performed in parallel until the rotation error of the two recognition marks 6 and 11 falls within the set range, and after the rotation error enters the set range, Although only the parallel movement control is performed, only the rotation control may be performed until the rotation error falls within the set range.

Note that, in the present invention, the chip mounting apparatus is not limited to the one configured as in the above embodiment, but may be any one of the head 1 and the substrate holding stage 2. It may be configured such that only one of the translation control and the rotation control can be performed.

For example, the head 1 is mounted on a movable table on the head side capable of controlling translation and rotation, but the substrate holding stage 2 is not mounted (fixed) as such, or The substrate holding stage 2 is mounted on the movable table on the stage side where parallel movement control and tillage control can be performed, but the head 1 is not mounted as such. ).

Even in such a chip mounting device, it is necessary to perform rotation control first so that the rotation direction error and difference are within the set range, and then, after completing the rotation control, perform parallel movement control and perform alignment. Therefore, the number of repetitions of the alignment can be reduced, so that the takt time can be shortened, and an alignment method can be obtained which has an effect of being able to perform the alignment with high accuracy. be able to.

In the present invention, the chip mounting device refers to a mounting device for mounting a chip, a bonding device for bonding the chip, or the like, and includes a heating type, a non-heating type, a pressure type, and a non-pressure type. A device with a broad concept that encompasses both.

Also, a chip refers to a semiconductor chip, an IC chip, an optical element, a wafer, or the like, a mounting object to be mounted or bonded to a substrate regardless of its type and size.

The substrate is, for example, a resin substrate, a glass substrate, a film substrate, or the like, and is an object on which the chip is mounted or bonded.

The two-view recognition means has two optical axes, for example, a recognition camera such as a CCD camera, an infrared camera, an X-ray camera, a sensor, or the like. Anything that can recognize (or image) the object. In addition, the head may be equipped with or without a heater, and the holding of the chip and / or the substrate may be performed by means other than vacuum suction. It may be holding. Also, regarding the recognition marks provided on the chip and the substrate, for example, only marks for specific purposes such as holes, grooves, printed marks, etc., their types and sizes, calibration, alignment, etc. Instead, any form may be used as long as it is suitable as a recognition mark. It should be noted that not only a pair but also a different form, for example, a single or two or more may be provided.

Further, the recognition means for recognizing the recognition mark 6 provided on the substrate and the recognition mark 11 provided on the chip is not limited to the recognition means 3 for the two visual fields provided in an integrated form. The axis and the lower optical axis may be provided in a form independent of each other (a form divided into two units) so that each of them can operate freely. Any camera, infrared camera, X-ray camera, sensor, etc. can be used as long as it can recognize (or image) the recognition mark.

In addition, as for the movable table which is a moving means of the substrate holding stage, the rotary table may not be provided at the top, that is, may be provided below the translation table. The one installed at the top is used. Industrial applicability

As described above, the alignment method in the chip mounting apparatus according to the present invention can perform high-precision alignment in a short time. Useful as a method.

Claims

The scope of the claims

1. Recognition means for recognizing a mark provided on a chip held by the head and a recognition mark provided on a substrate supported by a substrate holding stage provided below the head. And the translation control and the rotation control of only one of the head and the substrate holding stage so that the position difference between the two recognition marks is corrected to be within the target accuracy range. In an alignment method in a chip mounting apparatus configured to perform the rotation control, first, at least the rotation control is performed so that a rotation direction error between the two recognition marks is set within a set range. Then, after completing the above, only the parallel movement control is performed.

2. Recognize the recognition mark provided on the chip held by the head and the recognition mark provided on the substrate supported by the substrate holding stage provided below the head. Means for performing parallel translation control and rotation control of both the head and the substrate holding stage so that the recognition is performed by means and the positional deviation amount between the two recognition marks is corrected so as to be within the target accuracy range. In the alignment method for the chip mounting apparatus configured to be able to perform the above, first, at least the rotation control is performed so that the rotation direction error between the two recognition marks is within a set range, and then, after the completion thereof, An alignment method in a chip mounting apparatus, wherein only the parallel movement control is performed.

3. The method according to claim 2, wherein the head and the substrate holding stage are first set so that the rotation direction error between the two recognition marks is within a set range. The alignment control in the chip mounting apparatus is characterized in that at least rotation control of both is performed, and after that, only parallel movement control of one of the head and the substrate holding stage is performed. Method.

4. In the method according to claim 2, first, at least one of the head and the substrate holding stage is rotationally controlled so that the rotational direction error between the two recognition marks is within a set range. An alignment method in a chip mounting apparatus, which performs only parallel movement control of both the head and the substrate holding stage after the completion of the operation.

5. The method according to claim 2, wherein at least one of the head and the substrate holding stage is controlled to rotate so that the rotation direction error between the two recognition marks falls within a set range. And then, after the completion thereof, performing only the one of the parallel movement controls.

6. The method according to claim 2, wherein at least one of the head and the substrate holding stage is controlled to rotate so that the rotation direction error between the two recognition marks falls within a set range. And then, after the completion thereof, performing only parallel movement control of the other of the head and the substrate holding stage.

7. The method according to any one of claims 1 to 6, wherein the recognition means is a two-view recognition means.

8. The method according to any one of claims 1 to 7, wherein the head is provided with a heater.

9. The alignment method in a chip mounting apparatus according to claim 1, wherein the head is capable of holding a chip by vacuum suction.

Four