JPH10163214A - Bump bonder and bump formation - Google Patents

Abstract

PROBLEM TO BE SOLVED: To highly precisely form a bump to a wafer by effectively performing position regulation of the wafer by simple constitution. SOLUTION: A carrier which accommodates wafers in the state of lamination keeping suitable intervals is installed in a lifter. The wafers taken out from the carrier sequentially with a taking-out means are positioned in order on a transfer station. To the wafer transferred on a bonding stage from the transfer station, a bump is formed with a bonding head. In this bump bonder, positioning bars 50 regulating the wafer position in the carrier to the lifter, and a movable shutter 51 are installed. An orientation flat position detecting means is installed and detects the position deviation of a shutter 51 when the position of an orientation flat la is deviated. Position regulating means 67, 73 of a wafer 1 are installed in the taking-out means.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bump bonder for forming a bump for electrical connection on an electrode portion of an IC chip by a wire bonding technique, and more particularly to a bump bonder for forming a bump in a state of a wafer before being divided into each IC chip. About bonders.

[0002]

2. Description of the Related Art Various types of bonders for electrically connecting an electrode of an IC chip to a package conductor by a wire bonding technique are introduced in "Semiconductor Handbook (Second Edition)" published by Ohmsha. FIG. 18 shows an example of a conventional wire bonding apparatus. The illustrated bonder is intended for a chip of a lead frame type IC or LSI. The lead frame is supplied from a magazine a on the loader side to a bonding station b through a universal feeder, where a wire is supplied by a bonding head c. Bonded. The lead frame after the wire bonding is subjected to an automatic appearance inspection and then stored in the unloader side magazine d.

[0003] Even with these conventional bonders for performing wire bonding, it is possible to form bumps for electrical connection on the electrode portion of the IC chip depending on how to use them. For example, Japanese Patent Application No. 8-249724 has proposed this. I have.

[0004]

With the recent demand for smaller and lighter portable electronic devices, IC chips have been significantly reduced in size, and IC chips have been transferred one by one to a bonding stage. Various technical difficulties, such as poor production efficiency, difficulty in handling IC chips during transfer, transfer by tray, etc., as well as accurate positioning, are difficult with a bump bonder that performs positioning and bonding. Appears all at once.

Therefore, it is conceivable to form bumps on each IC chip in a state of the wafer before the IC chips are individually separated by dicing. However, forming a bump in a wafer state involves various technical problems different from those of an IC chip, and it is necessary to solve these problems in practical use.

For example, wafers are accommodated in a stacked state on multi-stage shelves formed in a carrier and supplied to a bump bonder. However, since the wafers are accommodated in the carrier in a state of rattling, the wafers are stored in the carrier. After the wafer is pulled out from the positioning table and is positioned on the positioning table, the wafer is transferred to the bonding stage. The wafer is a disk-shaped part having a different diameter (hereinafter referred to as an orientation flat) formed by linearly cutting the outer periphery. The positioning table needs to regulate the center position of the wafer and accurately regulate the circumferential position of the orientation flat, and requires a rotary table and position regulating means from four directions. The structure becomes complicated, the positioning takes time, and the wafer contained in the carrier may fly out during operation. There are some problems such as.

If a large-area wafer is fixed and bumps are formed on the entire surface, the relative movement distance between the bonding head and the bonding stage becomes longer, and the arm length of the bonding operation mechanism must be increased. Therefore, there is a problem that it is mechanically difficult to obtain sufficient accuracy. Therefore, the wafer is divided into a plurality of sections in the circumferential direction,
When the formation of bumps in a certain section is completed, it is conceivable that the wafer is rotated around its center, the next section is positioned in the bump formation area, and bump formation in that section is performed.

At this time, if the stage on which the wafer is fixed is rotated, the stage is heated up to form bumps. Therefore, accurate and stable positioning is difficult due to thermal expansion and contraction of the rotating mechanism. There is a problem that there is, and also blows swirling air to the lower surface of the wafer,
It is conceivable that the wafer is lifted up and turned, and the turning stop timing is aimed at by a worker's visual observation or a timer.However, irregular movement of the wafer occurs due to slight turbulence of the swirling air, and rotation position unevenness is likely to occur, There are problems such as difficulty in stably and properly positioning.

When the bonding stage is heated up and the entire surface of the wafer is heated, the initially formed bumps are kept at a high temperature for a long time, and the bumps and the electrode material cause a metallurgical reaction, so that the bumps are formed. There is a problem that strength is reduced.

Further, at the time of start-up or trouble of ball formation, discard bonding is necessary to form a ball at the tip of the wire. In the case of an IC chip, a discard chip may be supplied and bonding may be performed. However, in the case of a wafer, it is not practical to make a discarded wafer. On the other hand, since there is a region around the wafer where no IC chip is formed, it is conceivable to perform discarding bonding at that location. However, there is a large risk that the surface of the product is soiled due to the discard bonding performed on the product, and the operator has to look for the discard bonding position when a ball is not formed, thus lowering the work efficiency.

In bonding, it is necessary to correct the bonding position data by detecting the position of each IC chip and the inclination of the reference line of the wafer with respect to the reference line of the stage. As shown in FIG.
IC chips 131a, 1a facing each other along the reference line
A straight line 133 connecting the center positions 132a and 132b of 31b.
, And the inclination 135 between the straight line 133 and the stage reference line 134 is usually considered.

However, the recognition camera mounted on the bonding head has a narrow field of view in order to recognize the position with high accuracy, and the recognition position of the IC chip to be recognized is near the both ends of the wafer 1 even if the inclination of the wafer 1 is slight. However, there is a problem that the camera deviates from the field of view, and therefore, a recognition camera with a wide field of view dedicated to tilt detection is required, and there is a problem in mechanical cost.

SUMMARY OF THE INVENTION An object of the present invention is to provide a bump bonder which can solve at least one of the above problems and can successfully form a bump on a wafer.

[0014]

SUMMARY OF THE INVENTION In order to achieve the above object, an invention according to claim 1 is a loading station provided with a lifter for installing carriers accommodating stacked wafers at appropriate intervals from each other. A transfer station in which wafers sequentially taken out by the take-out means from the carrier are sequentially positioned; and a bonding head bumps the wafer transferred from the transfer station onto the bonding stage by the transfer means. In a bump bonder having a bonding station for forming a wafer, the lifter is provided with an orientation flat position detection means for controlling the position of the wafer in the carrier and detecting the orientation flat position of the wafer,
The removal means is provided with a wafer position regulating means.

With this configuration, the position of the entire wafer in the carrier can be regulated while the carrier is installed on the lifter, and the position of the orientation flat can be detected. Therefore, when the position of the orientation flat is not appropriate, the operator corrects the position. Thus, the wafer can be transferred to the take-out means in a state where the orientation flats are all correct. In addition, the wafer positioned by sequentially lowering the lifter is properly transferred to the unloading means, and the position of the wafer can be regulated by the position regulating means, and the unloading means is moved to the next transfer station. The positioning can be performed with high accuracy. Therefore, the wafers can be sequentially taken out from the carrier and positioned with a simple configuration and without any particular time required for positioning. In addition, there is no possibility that the wafer accommodated in the carrier will jump out due to vibration during operation.

According to a second aspect of the present invention, in the first aspect of the present invention, the orientation flat position detecting means includes a pair of positioning bars which are engaged with the edge of the wafer in the carrier opposite to the orientation flat,
A shutter elastically moved and biased toward a position where the wafer in the carrier substantially engages with the orientation flat, and a sensor that detects when the shutter is out of the position substantially engaged with the orientation flat. It is provided.

With such a configuration, the positioning of the wafer in the carrier is restricted and the position of the orientation flat is simultaneously controlled by a simple configuration in which the positioning bar, the movable shutter and the sensor for detecting the position of the shutter are simply provided on the lifter. Whether it is correct or not can be detected.

According to a third aspect of the present invention, in the first aspect of the present invention, the position regulating means of the take-out means has a pair of positioning rollers disposed at an appropriate distance from the tip of a wafer receiving portion for receiving and supporting the wafer from the carrier. And a restricting portion provided with a pair of position restricting rollers that are movable in the direction of the distance from the base end of the wafer receiving portion and engage with the orientation flat of the wafer.

With this configuration, the pair of positioning rollers at the front end of the wafer receiving portion and the restricting roller are moved by a mechanism and an operation for merely receiving the wafer on the wafer receiving portion and moving the restricting portion toward the base of the wafer receiving portion. The position of the wafer including the position of the orientation flat can be positioned with high accuracy by the pair of position regulating rollers of the unit.

According to a fourth aspect of the present invention, in a bump bonder for forming bumps on a wafer supplied on a bonding stage by a bonding head, a pair of regulating rollers are disposed on both left and right sides of the upper surface of the bonding stage. In addition, there is provided a regulating portion which engages with the orientation flat of the wafer and presses the wafer toward the regulating roller on the opposite side to regulate the position of the wafer, and further comprises a reversing means for reversing the wafer.

According to such a configuration, the bumps can be formed in the other half by turning the wafer after forming the bumps in the half area of the wafer, and as a result, the bumps can be continuously formed on the entire surface of the wafer. The range of movement of the bonding head can be reduced as compared with the case of forming, and the rigidity and accuracy of the bonding head can be easily ensured accordingly, and high-precision bump formation can be realized at low cost. Also,
Regardless of the orientation of the wafer orientation flat,
The regulating portion is engaged with the orientation flat to press the wafer against the regulating roller, and the wafer can be positioned by the regulating portion and the regulating roller. Therefore, the wafer can be accurately positioned with a simple configuration.

The reversing means can be constructed as described in claim 5, but it is also possible to provide a reversing mechanism in the transfer means and use it as the reversing means.

According to a fifth aspect of the present invention, the reversing means in the fourth aspect of the present invention comprises: a floating air jetting means for floating the wafer; a turning air jetting means for turning the wafer; The apparatus includes a biasing air ejection port to be applied to the regulating roller pair and an orientation flat detection sensor disposed on the regulating roller side to which the wafer is applied.

With such a configuration, the wafer can be swung by the swirling air to be inverted while being floated by the air, so that a mechanical rotating mechanism is not required, and the wafer can be easily mounted even at a high-temperature bonding stage. The wafer can be swirled with a simple configuration, and at the time of the swirl, the air blown from the one-sided air ejection port hits the wafer against the pair of regulating rollers on one side, so irregularities on the wafer due to subtle turbulence of the swirling air The rotation is stopped when the orientation flat is detected by the orientation flat detection sensor, and the wafer is stably and properly positioned by positioning the wafer with the regulation unit and the regulation roller. Can be positioned.

According to a sixth aspect of the present invention, in a bump bonder for forming bumps on a wafer supplied on a bonding stage by a bonding head, a reversing means for reversing the wafer and a half of the bonding stage close to the bonding head are provided. Means are provided for setting the temperature of the bonding work area to a predetermined temperature as a bonding work area and setting the remaining non-work area to a temperature lower than the predetermined temperature.

With such a configuration, the bump can be formed in a half area of the wafer by inverting the wafer by the inversion means, and then the bump can be formed in the other half area by inverting the wafer. Item 4 exhibits the same effect as the invention of Item 4, and when the bump formed earlier in the bonding work area moves to the non-work area, it is brought to a low temperature state, so that it is exposed to high temperature for a long time after the bump is formed. In this case, it is possible to effectively prevent a decrease in the strength of the bumps caused when the bumps are formed.

According to a seventh aspect of the present invention, the bonding stage according to the sixth aspect of the present invention is configured by disposing a heat block below the stage plate, and disposing the heat block only below the bonding work area of the stage plate. Things.

With this configuration, the bonding work area can be easily controlled to a predetermined temperature by the heat block, and the non-work area can be set to a low temperature.

According to an eighth aspect of the present invention, in addition to the seventh aspect, a notch is formed in the stage plate in at least a portion of the non-working area adjacent to the bonding work area.

With such a configuration, the temperature of the entire non-work area can be set more effectively and evenly by a simple means of providing a notch.

According to a ninth aspect of the present invention, the bonding stage according to the sixth aspect of the present invention is configured such that a heat block is provided below the stage plate, and the control temperature of the heat block is set at a lower portion of the bonding work area of the stage plate. The temperature is set to a temperature suitable for a predetermined bonding operation, and to a predetermined preheating temperature in the lower part of the non-working area.

With this configuration, since the wafer is heated to the preheating temperature in the non-working area, the temperature of the wafer is not suddenly changed, and the reduction in the strength of the formed bumps can be reliably prevented.

According to a tenth aspect of the present invention, in a bump bonder for forming a bump on a wafer supplied on a bonding stage by a bonding head, a suction hole for sucking a chip for discarding bonding at a peripheral portion on the bonding stage. Is disposed.

With such a configuration, the operator can automatically move to the discarding bonding portion and perform the discarding bonding operation without having to search for the discarding bonding position in the event of a ball formation failure or the like. ,
In addition, there is no danger of soiling the surface of the product because the bonding is not performed on the wafer.

According to the eleventh aspect of the present invention, a bump is formed on substantially half of a wafer by using a half of the bonding stage close to the bonding head as a bonding work area, and then the wafer is inverted to form bumps on substantially the other half. At the time of forming a bump in the bonding work area, bumps are sequentially formed from a side apart from the boundary between the bonding work area and the non-work area from a side close to the boundary.

According to such a configuration, the same effect as that of the fourth aspect of the present invention is exhibited, and the bump formation is performed first from the side distant from the boundary between the bonding work area and the non-work area, so that the non-work area can be formed. Even if the work area near the boundary between the bonding work area and the bonding work area is exposed to high temperature due to the thermal effect of the bonding work area, the bumps formed at the part near the boundary between the bonding work area and the non-work area are exposed to the high temperature. It is possible to prevent a reduction in the strength of the bumps on the entire surface of the wafer without lengthening the time.

According to a twelfth aspect of the present invention, a wafer is mounted on a plurality of ICs.
Divided into blocks grouped for each chip, bumps are formed for each block, and the detection of wafer inclination required for correcting bonding position data at that time is performed for IC chips corresponding to each other in the direction of the wafer reference line in an adjacent block. The detection is performed based on the inclination between the straight line connecting the centers and the reference line of the bonding stage, and the position of the recognition window at the time of detecting the next inclination is corrected based on the detection result.

According to such a configuration, I
By recognizing the position of the C chip and the inclination of the wafer and bonding, the number of times of recognition can be reduced while absorbing the thermal expansion of the wafer, and accurate and highly productive bonding can be performed. Since the recognition window position at the time of the next recognition is corrected based on the detection result and the detection result, the tilt can be detected with high efficiency by a short recognition operation without requiring a recognition camera having a wide field of view dedicated to tilt detection.

[0039]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a representative embodiment of the present invention will be described with reference to FIGS.

First, the overall arrangement of the bump bonder of this embodiment will be described with reference to FIG. 1. A loading station 2 for loading a carrier containing a wafer 1 and a loading station for positioning a wafer pulled out of the carrier. Transfer station 3, a bonding station 4 for forming bumps, an unloading transfer station 5 on which the bumped wafer 1 is positioned, and a wafer 1 on which bumps are formed are sequentially accommodated in a carrier. And an unloading station 6 for unloading are arranged at equal intervals on the line. At the front of the wafer 1 transfer line, there are provided unloading means 7 for unloading the wafer 1 from the loading station 2 to the loading transfer station 3 and insertion means for inserting the wafer 1 from the unloading transfer station 5 to the unloading station 6. 8 are provided. Further, a transfer means 9 for transferring the wafer 1 from the loading-side transfer station 3 to the bonding station 4 and transferring the wafer 1 from the bonding station 4 to the unloading-side transfer station 5 is provided at the front thereof. I have.

In the bonding station 4, a bonding stage 10 composed of a heat stage is provided for bonding by ultrasonic thermocompression bonding, and a bonding head 11 is provided behind the bonding stage. The bonding head 11 is supported so as to be movable in the XY2 directions, and has an X-axis motor 12a and a Y-axis motor 1a.
2b, it is mounted on an XY table 12 which can be moved and positioned at any position in the X and Y directions.

As shown in FIG. 2, the bonding head 11 passes a wire reel 13 and a wire 14 from the wire reel 13 from above to bond the wafer 1 to be bonded on the bonding stage 10 to the wafer 1. A wire tensioner 17 that blows up the middle of the wire 14 from the wire reel 13 to the bonding work mechanism 15 in an upwardly curved state by air 16 to apply tension to the wire 14 between the bonding work mechanism 15 and the bonding work mechanism 15; A wire tensioner 21 is disposed above the wire guide 18a of the clamper 18 at 15 to expose the wire 14 to upward air 20 and apply an upward tension to the wire 14. 1
At 7 and 20, it is configured to be able to supply to the bonding work mechanism 15 without difficulty while floatingly supporting it so as to maintain a predetermined supply path and tension.

The bonding operation mechanism 15 is shown in FIGS.
As shown in FIG. 5, a clamper 18 for gripping the wire 14,
A horn 22 for applying ultrasonic vibration to a ball 14a having a capillary 22a through which the wire 14 is inserted at the tip and a formed torch 14a, and a torch 23 for discharging are provided. A recognition camera 24 for visually recognizing the state of the bonding operation is provided at an upper portion, and displays a recognition image on a recognition monitor (not shown) and inputs a recognition signal to a data processing device (not shown). It is configured to process data. Further, there are provided a vertically moving electromagnetic drive unit 25 for reciprocatingly rotating the bonding work mechanism 15 around a fulcrum shaft (not shown) to move the tip end up and down, and an opening and closing electromagnetic drive unit 26 for opening and closing the clamper 8.

The bonding operation will be described with reference to FIG. 4. The wire 14 is sent out through a capillary 22a, and each time the bonding head 11 moves to a position facing a predetermined electrode 27 of the wafer 1, the torch 23 is moved.
The tip portion is melted by the spark current from, and a ball 14a is formed as shown in FIG. The position of the wire 14 facing each electrode 27 is controlled with high precision under the visual recognition of the recognition camera 24. Formed ball 1
4a is bonded to the electrode 27 of the wafer 1 by thermocompression bonding and ultrasonic vibration as shown in FIG. The pressing force at this time is preferably about 30 g to 50 g, the ultrasonic vibration is applied in the horizontal direction, the amplitude is 0.5 μm, and the frequency is 60 to 50 g.
70KH _Z (specific examples include 63.5KH _Z) is preferred to be about. Next, the upward movement of the clamper 18 and the capillary 22a holding the wire 14 causes
The wire 14 is cut as shown in FIG.
And a ball 14a and 30 μm to 4
A bump 28 having a protrusion length of about 60 μm and a wire portion 14 b protruding to a height of about 0 μm is formed. As the wire 14, a wire having a high Young's modulus and a low thermal conductivity is used so that the above-mentioned cutting is reliably performed at a predetermined position.

Next, the movement, transfer, and positioning of the wafer 1 between the stations 2 to 6 will be sequentially described. First, the carrier 30 for loading and unloading the wafer 1 will be described with reference to FIG. Will be explained. Carrier 3
Numeral 0 denotes a case where the wafer 1 is accommodated in a stacked state with a plurality of upper and lower wafers spaced at appropriate intervals from each other. The front and rear surfaces are opened and the rear portion is tapered toward the rear end so that the wafer 1 does not come out backward. A multi-stage (24-stage in the illustrated example) receiving shelf row 32 is formed of a narrowed substantially rectangular frame-shaped frame body, and the both side walls 31 are fitted and supported on both sides of each wafer 1. On the lower surface of the H-shaped bottom wall 33, a rib 34 crossing in the left-right direction is protrudingly provided.

The carry-in station 2 is provided with a lifter 40 as shown in FIGS. 6 to 8, and the carrier 30 is mounted on the lift table 41 from above. The lifting table 41 is vertically movably supported via two slide guides 44 by two right and left vertical guide shafts 43, the upper and lower ends of which are held by a fixed frame 42, and a servomotor mounted on the back of the fixed frame 42. The lifting and lowering operation is performed by a timing belt 45 driven forward and reverse by the rotation. The carrier 3 is provided on the upper surface of the lift 41.
Four positioning pins 47 for engaging and positioning with the 0 positioning portion 35 are provided in a protruding manner. A spring 4 is provided so as to elastically press the carrier 30 on the lift table 41 from above.
At 9, a holding lever 48 urged toward a horizontal posture so as to be able to retreat and rotate upward is provided. By the elevating operation of the elevating table 41, each wafer 1 accommodated in the carrier 30 is sequentially positioned at a predetermined take-out height position from the lowest one.

Further, with the unloading direction of the wafer 1 from the carrier 30 being the front, a pair of positioning members engaging with both sides of the rear edge of the wafer 1 in the carrier 30 are provided at the rear portion (right end portion in the drawing) of the lift table 41. A bar 50 is provided upright. Further, a shutter 51 that enters the front surface of the carrier 30 and substantially engages with the orientation flat 1a of the wafer 1 housed therein extends from the fixed frame 42 side. The lower end of the shutter 51 is located slightly above the take-out height position of the wafer 1 and is arranged so as not to interfere with the take-out operation of the wafer 1. The shutter 51 is shown in FIGS.
As shown in FIG. 7, a slide member 53 is mounted on the rear side of the fixed frame 42 by a slide guide 52 so as to be movable in the take-out direction, and urges the slide member 53 rearward in the take-out direction. A stopper against which the sliding member 53 abuts so that the shutter 54 stops at a position where a minute gap (about 0.5 mm) is left between the spring 51 and the orientation flat 1a while the wafer 1 abuts the positioning bar 50. 55
And a sensor 56 for detecting when the sliding member 53 does not move to the position where it contacts the stopper 55. When the wafer 1 is positioned by the positioning bar 50 and the shutter 51, and the position of the orientation flat 1a is not correctly positioned in front, the sliding member 53
Does not come into contact with the stopper 55 and is detected by the sensor 56. The above mechanism constitutes an orientation flat position detecting means 57 for roughly positioning the wafer 1 on the lifting platform 41, preventing the wafer 1 from jumping out of the carrier 30, and detecting the position of the orientation flat 1a of the wafer 1. . Reference numeral 58 denotes a limit switch for detecting the ascending or descending limit position of the elevating platform 41, the safety stop position when the position is exceeded, and the origin position.

FIG. 9 shows a lifter 40A of the unloading station 6. The lifter 40A is also in the loading station 2
Has the same structure as that of the lifter 40, and the corresponding components are denoted by the same reference numerals, and only the differences will be described. In the lifter 40A, since the positioning bar 50 and the sensor 56 of the sliding member 53 are unnecessary, they are not provided, and a carrier presence / absence detection sensor 58 for detecting the presence / absence of the carrier 30 is provided. In this lifter 40A, the shutter 5
1 may be fixedly provided.

Next, the removal means 7 and the insertion means 8 will be described with reference to FIGS. Since both have almost the same configuration, the extraction means 7 will be mainly described and the insertion means 8 will be described only on the differences.

In FIG. 10, the lower portion of the movable support member 63 is supported by a slide guide 61 disposed on the rear side of the front fixed frame 60 so as to be reciprocally movable in the left-right direction (the direction in which the wafer 1 is taken out). Similarly, it is connected to a movable portion 62a of a rodless cylinder 62 disposed on the rear side of the front fixed frame 60 so as to be driven and positioned. A base 65 a of a support arm 65 is provided above the movable support member 63 via a slide guide 64.
3 so as to be movable in the direction of movement.
A wafer receiving portion 66 for receiving and supporting the wafer 1 from below is provided at a leading end extending toward the lift table 41 side, and a pair of positioning rollers 67 are provided on both sides of the leading end.
The base 65 a of the support arm 65 is moved to a stopper 69 by a spring 68.
And a sensor 70 for detecting when the wafer receiving portion 66 collides with an obstacle and moves against the spring 68 during the movement. The operation is immediately stopped to prevent breakage.

A base 72 a of a regulating arm 72 is attached to a base 65 a of the supporting arm 65 via a cylinder 71 with a guide so as to be movable in the moving direction of the movable supporting member 63. A restricting portion 73 facing the base end of the wafer receiving portion 66 is provided at an appropriate interval, and a pair of position restricting rollers 74 that engage with the orientation flat 1a of the wafer 1 are provided at the distal end thereof. Then, the base 72a of the regulating arm 72 is constantly moved and biased by the spring 71a so that the regulating portion 73 at the distal end approaches the wafer receiving portion 66 side, and the guide cylinder 71 opposes the biasing force of the spring 71a. It is configured to be driven apart. An orientation flat detection sensor 75 for detecting the orientation flat 1a is provided on one side of the regulating section 73.

Thus, as shown in FIG.
5 Insert the wafer receiving portion 66 at the leading end below the lowermost wafer 1 in the carrier 30 to position the positioning roller 67.
Is positioned outside the outer peripheral edge of the wafer 1, and in this state, the elevating table 41 is lowered to support the wafer 1 on the wafer receiving portion 66, and then the regulating arm 72 is moved with respect to the supporting arm 65 to position the positioning roller. Spring 7 with 67 and position regulating roller 74
The position of the wafer 1 is regulated by holding the wafer 1 with an appropriate load by the urging force 1a. Further, the orientation flat detection sensor 75 confirms that the position of the orientation flat 1a is correct. In addition, this regulating arm 72 is
A sensor 76 for detecting that the gap between the position 7 and the position regulating roller 74 is open, a sensor 77 for detecting that the regulating arm 72 has moved further since the wafer 1 is not present, and the wafer 1 are properly pinched at the orientation flat 1a position. And a sensor 78 for detecting movement to the specified position. And
The positioning roller 67 and the position regulating roller 74 constitute a position regulating means 79 for the wafer 1.

In the insertion means 8, the wafer receiving portion 66
Since it is only necessary to insert the upper wafer 1 into the carrier 30 of the unloading station 6, the regulating arm 72 and its related components are not provided. Instead, the suction chuck 80 is provided in the wafer receiving portion 66. I have.

Next, the transfer means 9 will be described with reference to FIG. A moving table 82 is provided, which is driven by moving means 81 parallel to the moving line of the wafer 1 and is capable of moving and positioning between the loading-side transfer station 3, the bonding station 4, and the unloading-side transfer station 5. . The moving means 81 is configured to rotationally drive a ball screw 83 disposed in the moving range by a servomotor 84, and a nut body screwed to the ball screw 83 is fixed to the moving body 82. The moving body 82 includes an elevating body 85
Is movably mounted in the vertical direction, is constantly biased toward the upper limit position by a spring 85a, and is driven to move to the lower limit position by a built-in cylinder. A chuck means 86 extends from the upper end of the elevating body 85 directly above the moving line of the wafer 1. The chuck means 86 includes a pair of chuck rods 87 which can be approached and separated from each other by a cylinder 86a, and a pair of chucking pins 88 are respectively suspended from the chuck rods 87 via a floating mechanism 89. A lower end of the chucking pin 88 is provided with a flange 88a for preventing the wafer 1 from falling.

Thus, the chucking means 86 at the loading-side transfer station 3 or the bonding station 4 is used.
The lifting body 85 is lowered while the chucking means 8 is open.
6 is closed, the wafer 1 is gripped by the four chucking pins 88, and then the elevating body 85 is raised to the upper limit position, and the moving body 82 is connected to the movable portion 62a of the bonding rodless cylinder 62 by the moving means 81. It is configured to be driven and positioned. Movable support member 63
A base 65a of a support arm 65 is movably mounted in the moving direction of the movable support member 63 via a slide guide 64, and is moved to the position of the station 4 or the unloading side transfer station 5 to move the elevating body 85. The wafer 1 can be transferred by lowering it and opening the chuck means 86. At this time, since the chucking pins 88 are vertically provided via the floating mechanism 89, there is no possibility that the wafer 1 will be chipped during chucking.

Next, the bonding stage 10 will be described with reference to FIGS. A stage plate 91 and a heat block 92 below the stage plate 91 are provided. On the upper surface of the stage plate 91, a total of four regulating rollers 93 are provided on each side so that the wafer 1 is fitted with a margin. Stage plate 91
A pair of contact rollers 9 that engage with the orientation flat 1a
4 are provided so as to face the respective pairs of regulating rollers 93 located on opposite sides.
At 5, the position of the wafer 1 is regulated by pressing the wafer 1 against the regulating roller 93. The restricting portion 95 is constantly urged in the restricting direction by a spring 96, and a cylinder (not shown) for driving to move in the restricting release direction is disposed on the back side of the stage plate 91. In addition, an orientation flat detection sensor 97 for detecting the orientation flat 1a is arranged near one of the regulating portions 94 (right side in the drawing).

The stage plate 91 has a suction / floating air port 101 for sucking and floating the wafer 1,
The swirling air jet port 102 is opened by being inclined obliquely in the same direction in the circumferential direction so as to turn the wafer 1, and the wafer 1 is swung so that the wafer 1 does not wobble when the wafer 1 turns. A one-sided air ejection port 103 for urging toward one of the pair of regulating rollers 93 (right side in the figure) is provided. The offset air jet 103 is arranged inside the radius of the swirling airflow so as not to interfere with the swirling airflow ejected from the swirling air jet 102,
The suction / floating air port 101 is disposed outside and inside the radius of the swirling airflow. Also, the stage plate 91
Is disposed at an appropriate position on the periphery of the chip, and a suction hole 1 for sucking a chip for discard bonding is provided.
04a is provided.

In the heat block 92, several cartridge heaters 105 are inserted, and a thermocouple 106 is buried, so that the temperature is controlled at about 270 ° C. The heat block 92 is supported by a pair of left and right leg members 107 having high heat dissipation.

Thus, when the wafer 1 is transferred by the transfer means 9 to the inside of the four control rollers 93 on the bonding stage 10 toward the left side in FIGS. 95, the contact roller 94 is engaged with the orientation flat 1a to press the wafer 1 against the pair of right regulating rollers 93, and the position of the wafer 1 is regulated by the contact roller 94 and the regulating roller 93. I do. In this state, the wafer 1 is suction-fixed by the suction / floating air port 101, and the wafer 1 is
IC in the half area near the bonding head 11
A bump 28 is formed on the chip.

Next, the suction of the wafer 1 and the restriction by the restriction part 95 on the left side are released, and the suction / floating air port 101 is used.
Air is blown out from the wafer to float the wafer 1,
Air is blown out from the biasing air outlet 103 to engage the wafer 1 with the pair of regulating rollers 93 on the right side in the figure, and in this state, air is blown out from the turning air outlet 102 to turn the wafer 1. As described above, by engaging the wafer 1 with the pair of regulating rollers 93 when the wafer 1 rotates, the wafer 1 can be swung at a fixed position without whirling and wobbling. Then, the wafer 1 is moved to a position where the orientation flat 1a of the wafer 1
Is detected by the orientation flat detection sensor 97, the levitation and the rotation are immediately stopped, and the right regulating unit 9 is rotated.
5 and the contact roller 94 is moved to the orientation flat 1a.
, And presses the wafer 1 against the pair of left-hand regulating rollers 93, and the contact roller 94 and the regulating roller 9 are pressed.
At 3, the position of the wafer 1 is regulated. In this state, the wafer 1 is suction-fixed by the suction / floating air port 101, and the bonding head 11 of the wafer 1 is
The bumps 28 are formed on the other half of the IC chip on the side closer to the wafer 1, and the formation of the bumps 28 on the entire surface of the wafer 1 is completed.

As described above, by forming the bumps on the wafer 1 in half of the area, the moving range of the bonding head 11 can be reduced, whereby the rigidity and the dimensional accuracy of the bonding head 11 are secured and the bumps are formed with high precision. Can be realized.

When a ball unforming trouble or the like occurs during the bump forming operation and discard bonding is required, the bonding head 11 is moved to the stage plate 9.
1 a dedicated discard bonding section 104 set on
Then, the ball is formed by automatically moving the chip and bonding the discarded chip, and the normal bump forming operation can be promptly and efficiently returned to the normal operation. The provision of such a dedicated discarding bonding portion 104 reduces the work efficiency as in the case where discarding bonding is performed by searching for a discardable bonding area around the wafer 1, or the wafer 1 The possibility of soiling the surface can be eliminated.

If the bump 28 is exposed to a high temperature for a long time after it is formed, the strength of the bump 28 may decrease due to a metallurgical reaction between the bump 28 and the material of the electrode 27. However, it takes a long time to form the bumps 28 on the entire surface of the wafer 1 and, as shown in FIGS.
In the illustrated example, since the entire surface of the stage plate 91 is uniformly heated to a predetermined temperature by the heat block 92 disposed on the lower surface, the strength of the bump 28 formed earlier may be reduced.

To solve such a problem, FIG.
As shown in (a) and (b), by disposing the heat block 92 only in the lower part of the bonding work area 110 (indicated by diagonal lines) corresponding to the half of the stage plate 91 on the side close to the bonding head 11, the remaining In the non-work area 111 where no bonding is performed, the stage plate 91 is used.
In addition, the temperature of the wafer 1 may be reduced. At this time, the bonding work area 110 is used even in the non-work area 111.
In the portion near the boundary between the bonding work area 110 and the non-working area 111, the bumps are formed not on the side near the boundary between the bonding working area 110 and the non-working area 111 but on the side near the bonding head 11, In this case, the time for exposing the bumps 28 formed near the boundary between the bonding work area 110 and the non-work area 111 to a high temperature does not become long, and the bumps 28 on the entire surface of the wafer 1 A decrease in strength can be prevented.

As shown in FIG. 15C, a heat block 92 is arranged on the entire lower surface of the stage plate 91, and a cartridge heater 105a corresponding to the bonding work area 110 and a cartridge heater 105 corresponding to the non-work area 111 are provided. For example, the temperature of the cartridge heater 105a may be controlled to 270 ° C., and the temperature of the cartridge heater 105b may be controlled to about 100 ° C. for preheating the wafer 1. Further, as shown in FIG.
In addition to the configurations of (a) and (b), a notch 112 is formed in the stage plate 91 at the central portion where the temperature is likely to be high due to the heat of the heat block 92 in the non-work area 111, and the heat transfer by the stage plate 91 is performed. It is also possible to prevent the temperature from becoming high.

At the time of the bonding operation,
As shown in FIG. 6, a large number of ICs formed on the wafer 1
The wafer 1 is divided into a plurality of blocks 122 by grouping a plurality of chips 121, and a bonding operation is sequentially performed for each block 122. In the bonding operation, the position of each IC chip and the bonding stage 1
Bonding is performed while correcting the bonding position data by detecting the inclination of the reference line of the wafer 1 with respect to the reference line of 0. In order to detect the reference line of the wafer 1, the wafer 1 is moved between adjacent blocks 122, 122. The center position 121a of the IC chips 121, 121 corresponding to each other in the direction parallel to the reference line is obtained, and the center position 121a is obtained by a straight line 123 connecting the centers 121a, 121a. And the straight line 123
Between the reference line 124 of the bonding stage 10 and the reference line 124
25, and the IC chip 121 in the block 122 is obtained.
The bonding position data is corrected based on the detected position and the detected inclination 125, and the bonding operation of each IC chip 121 is sequentially performed.

When the bonding operation of one block 122 is completed, the process moves to the next block 122 and the same operation is repeated. At this time, a window for recognizing the IC chip 121 set for detecting the inclination 125 is set. 1
26 sets the IC chip 121 corresponding to the adjacent block 122 even if the field of view of the recognition camera 24 mounted on the bonding head 11 is narrow by setting the corrected position based on the previously detected tilt 125. The tilt 125 can be reliably detected within the field of view.

As described above, bonding is performed by recognizing the position of the IC chip 121 and the inclination of the wafer 1 for each block 122, thereby reducing the number of times of recognition while absorbing the thermal expansion of the wafer 1 and improving the productivity and accuracy. High bonding performance. Further, the tilt can be detected with high efficiency by a short recognition operation without requiring a recognition camera having a wide field of view dedicated to tilt detection.

[0069]

According to the first aspect of the present invention, the lifter is provided with the orientation flat position detecting means for regulating the wafer position in the carrier and detecting the orientation flat position of the wafer, and the take-out means is provided with the wafer position regulating means. Since the position of the entire wafer in the carrier can be restricted and the position of the orientation flat can be detected while the carrier is installed on the lifter, the operator corrects the orientation flat when the position of the orientation flat is not appropriate. The wafer can be delivered to the unloading means in a correct state, and the positioned wafer can be properly received on the unloading means, and the position of the wafer can be regulated by the position regulating means, and the unloading means can be transferred to the next transfer station. By moving and positioning, the wafer can be positioned with high accuracy. Therefore, the wafer can be sequentially taken out of the carrier and positioned with high accuracy with a simple configuration and no time is required for the positioning, and there is a possibility that the wafer accommodated in the carrier may fly out due to vibration during operation. It has the effect of not having.

According to the second aspect of the present invention, the orientation flat position detecting means is provided between a pair of positioning bars which are engaged with the edge of the wafer in the carrier opposite to the orientation flat, and the orientation flat of the wafer in the carrier. Since it is composed of a shutter elastically moved and biased toward the position where it is substantially engaged and a sensor which detects when the shutter is out of the position where it is substantially engaged with the orientation flat, it is positioned on the lifter. With a simple configuration in which a bar, a movable shutter and a sensor for detecting the position of the shutter are provided, the position of the orientation flat can be detected at the same time as the position of the wafer in the carrier is regulated.

According to the third aspect of the present invention, a pair of positioning rollers disposed at appropriate intervals at the tip of a wafer receiving portion for receiving and supporting a wafer from a carrier, and Since a pair of position regulating rollers, which are movable in the near and far directions with respect to the base end of the receiving portion and engage with the orientation flat of the wafer, are constituted by the disposed regulating portion, the wafer is received on the wafer receiving portion. With a mechanism and operation that merely moves the regulating portion toward the base of the wafer receiving portion, the pair of positioning rollers at the tip of the wafer receiving portion and the pair of position regulating rollers of the regulating portion move the wafer including the orientation flat position. The position can be positioned with high precision.

According to the fourth aspect of the present invention, a pair of regulating rollers are provided on both left and right sides of the upper surface of the bonding stage, and are engaged with the orientation flat of the wafer to press the wafer toward the opposite regulating roller. Since a regulating portion for regulating the position of the wafer is provided, and a reversing means for reversing the wafer is provided, the wafer can be reversed to form bumps half by half, and the moving range of the bonding head can be reduced accordingly. The rigidity and accuracy of the bonding head can be easily secured, high-precision bump formation can be realized at low cost, and the wafer can be held by the regulating unit and the regulating roller regardless of the orientation of the wafer. Since the positioning can be performed, the wafer can be accurately positioned with a simple configuration.

According to the fifth aspect of the present invention, the reversing means includes a floating air jetting means for floating the wafer, a swirling air jetting means for turning the wafer, and a pair of regulating rollers for rotating the wafer in one side. It is composed of a one-sided air ejection port to be applied to the wafer and an orientation flat detection sensor arranged on the side of the regulating roller to which the wafer is applied, so that the wafer can be turned and inverted while floating by air. The wafer can be swiveled with a simple configuration even at the high temperature bonding stage, and the wafer is swung by contacting the pair of regulating rollers on one side, so irregular movement of the wafer due to subtle turbulence of the swirling air The rotation is stopped when the orientation flat is detected, and the wafer is stably and properly positioned by positioning the wafer with the regulating unit and the regulating roller. It is possible to fit-decided.

According to a sixth aspect of the present invention, in a bump bonder for forming a bump on a wafer by a bonding head on a bonding stage, a reversing means for reversing the wafer and a half of the bonding stage close to the bonding head are bonded. A means for setting the temperature of the bonding work area to a predetermined temperature as a work area and setting the remaining non-work area to a temperature lower than the predetermined temperature is provided. 5. The method according to claim 4, wherein the step of forming the bumps in the region allows the wafer to be turned over to form the bumps in the other half of the region.
The same effect as that of the invention can be obtained, and when the bump formed earlier in the bonding work area is moved to the non-work area, the temperature is set to a low temperature state. The resulting reduction in the strength of the bumps can be effectively prevented.

According to the seventh aspect of the present invention, the bonding stage is configured by disposing a heat block below the stage plate, and the heat block is disposed only below the bonding work area of the stage plate. The bonding work area can be easily controlled to a predetermined temperature by the heat block, and the non-work area can be set to a low temperature.

According to the eighth aspect of the present invention, the notch is formed in the stage plate in at least a part of the non-working area adjacent to the bonding work area. Therefore, the temperature of the entire non-work area can be set more effectively and uniformly.

According to the ninth aspect of the present invention, a temperature suitable for a predetermined bonding operation is set below the bonding work area of the stage plate in the heat block, and a predetermined preheating temperature is set below the non-working area. Therefore, it is possible to surely prevent a drop in the strength of the formed bumps without giving a rapid temperature change to the wafer.

According to the tenth aspect of the present invention, in a bump bonder for forming a bump on a wafer supplied on a bonding stage by a bonding head, a chip for discarding is attracted to a peripheral portion on the bonding stage. Disposal bonding part with suction holes is arranged, so that when a ball is not formed, the ball can be automatically formed at the disposal bonding part and normal operation can be resumed, improving work efficiency and improving product efficiency. The effect is that there is no danger of soiling the surface because the discard bonding is not performed.

According to the eleventh aspect of the present invention, after forming a bump on substantially half of the wafer using a half of the bonding stage close to the bonding head as a bonding work area, the wafer is inverted and bumps are formed on substantially the other half. At the same time, when forming bumps in the bonding work area, bumps are sequentially formed from the side distant from the boundary between the bonding work area and the non-work area from the side close to the boundary,
While exhibiting the same effect as the invention of claim 4 above,
By performing bump formation from the side farther from the boundary between the bonding work area and the non-working area, the portion of the non-working area near the boundary with the bonding work area is exposed to high temperature due to the thermal effect of the bonding work area. However, it is possible to prevent the bump formed at the portion near the boundary between the bonding work area and the non-work area from being exposed to a high temperature for a long time, thereby preventing a reduction in the strength of the bump on the entire surface of the wafer.

According to the twelfth aspect of the present invention, the wafer is divided into blocks grouped for each of a plurality of IC chips, bumps are formed for each block, and the inclination of the wafer required for correcting bonding position data at that time is detected. Is detected by the inclination between the straight line connecting the centers of the IC chips corresponding to each other in the direction of the wafer reference line in the adjacent block and the reference line of the bonding stage, and the recognition window position at the time of detecting the next inclination is corrected based on the detection result. Therefore, by performing bonding by recognizing the position of the IC chip and the inclination of the wafer for each block, the number of times of recognition can be reduced while absorbing the thermal expansion of the wafer, and bonding with high accuracy and high productivity can be performed. The tilt can be detected with high efficiency by a short recognition operation without requiring a recognition camera having a wide field of view dedicated to detection.

[Brief description of the drawings]

FIG. 1 is a plan view showing the overall arrangement of a bump bonder according to an embodiment of the present invention.

FIG. 2 is a perspective view of a wire supply mechanism in the bonding head of the embodiment.

FIG. 3 is a perspective view showing the bonding head of the embodiment without a wire supply mechanism;

FIG. 4 shows a bonding operation process of the embodiment;
(A) is a sectional view of a ball forming step, (b) is a sectional view of a step of bonding a ball to an electrode, and (c) is a sectional view of a step of cutting a wire to form a bump.

FIGS. 5A and 5B show a wafer transfer carrier according to the embodiment, wherein FIG. 5A is a cross-sectional plan view taken along line AA of FIG.
Is a front view, and (c) is a bottom view.

FIG. 6 is a perspective view showing a main configuration of a lifter provided in the carry-in station of the embodiment.

FIG. 7 is a perspective view of a main part of the lifter of FIG. 6 as viewed from the rear side.

FIG. 8 is a plan view showing an orientation flat position detecting means in the lifter of FIG. 6;

FIG. 9 is a perspective view showing a configuration of a main part of a lifter provided in the unloading station of the embodiment.

FIG. 10 is a perspective view showing a schematic configuration of an extraction unit and an insertion unit of the embodiment.

FIG. 11 shows an operation state of the extraction unit of the embodiment,
(A) is a front view, (b) is a plan view.

FIG. 12 is a perspective view of the transfer means of the embodiment.

FIG. 13 is a perspective view of a bonding stage of the embodiment.

FIG. 14 is a plan view of the bonding stage.

15A and 15B show a modified configuration example of the bonding stage of the embodiment, wherein FIG. 15A is a plan view of a first modified example, FIG. 15B is a perspective view of the same, and FIG. 15C is a plan view of a second modified example. (D) is a plan view of the third modification.

FIGS. 16A and 16B are explanatory diagrams of the bonding operation method of the embodiment, wherein FIG. 16A is an explanatory diagram of a block setting state for a wafer, and FIG. 16B is an explanatory diagram of a method of detecting the details of a block and the inclination of a reference line of the wafer; is there.

FIG. 17 is an explanatory diagram of a conventional method for detecting the inclination of a reference line of a wafer.

FIG. 18 is a front view of a conventional bonder for performing wire bonding.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 wafer 1a orientation flat 2 loading station 3 loading side transfer station 4 bonding station 7 removal means 9 transfer means 10 bonding stage 11 bonding head 30 carrier 40 lifter 50 positioning bar 51 shutter 53 sliding member 54 spring 55 stopper 56 sensor 57 orientation flat Position detecting means 66 Wafer receiving part 67 Positioning roller 73 Restriction part 74 Position restriction roller 79 Position restriction means 91 Stage plate 92 Heat block 93 Restriction roller 95 Restriction part 97 Ori-flat detection sensor 101 Suction / floating air port 102 Swirl air outlet Reference Signs 103 Air ejection port for biasing 104 Discard bonding section 104a Suction hole 110 Bonding work area 111 Non-work area 112 Notch 121 IC chip 122 Lock 123 linear 124 stage reference line 125 tilt 126 window

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Masaya Watanabe 1006 Kazuma Kadoma, Osaka Pref. Matsushita Electric Industrial Co., Ltd. 72) Inventor Kiyoshi Umayahara 1006 Kadoma Kadoma, Osaka Prefecture Matsushita Electric Industrial Co., Ltd.

Claims (12)

[Claims] 1. A carry-in station provided with a lifter for installing a carrier in which stacked wafers are housed at an appropriate distance from each other, and a transfer station in which wafers sequentially taken out of the carrier by an unloading means are sequentially positioned. And a bonding station for forming a bump with a bonding head on a wafer transferred from a transfer station to a bonding stage by a transfer means, the lifter restricts a wafer position in the carrier. A bump bonder further comprising: an orientation flat position detecting means for detecting the orientation flat position of the wafer; and a wafer position regulating means for the unloading means. 2. An orientation flat position detecting means, comprising: a pair of positioning bars engaged with an edge of the wafer in the carrier opposite to the orientation flat; and a position substantially engaged with the orientation flat of the wafer in the carrier. 2. The bump bonder according to claim 1, further comprising a shutter that is elastically moved and urged, and a sensor that detects when the shutter is out of a position where the shutter is substantially engaged with the orientation flat. 3. A position control means of the unloading means, comprising: a pair of positioning rollers disposed at an appropriate distance from a front end of a wafer receiving portion for receiving and supporting a wafer from a carrier; 2. A bump bonder according to claim 1, further comprising a restricting portion provided with a pair of position restricting rollers movable in a perspective direction and engaging with the orientation flat of the wafer. 4. A bump bonder for forming bumps on a wafer supplied onto a bonding stage by a bonding head, wherein a pair of regulating rollers are disposed on both right and left sides of an upper surface of the bonding stage, and a pair of regulating rollers are provided on the wafer orientation flat. A bump bonder provided with a regulating portion that engages and presses a wafer toward a regulation roller on the opposite side to regulate the position of the wafer, and further includes a reversing means for reversing the wafer. 5. A reversing means, a floating air jetting means for floating a wafer, a turning air jetting means for turning a wafer, and a biasing air jet for hitting the turning wafer to a pair of regulating rollers on one side. 5. The bump bonder according to claim 4, further comprising an outlet, and an orientation flat detection sensor disposed on the side of the regulating roller to which the wafer is applied. 6. A bump bonder for forming a bump on a wafer supplied on a bonding stage by a bonding head using a reversing means for reversing the wafer and a half of the bonding stage near the bonding head as a bonding work area. A bump bonder comprising means for setting the temperature of a bonding work area to a predetermined temperature and setting the remaining non-work area to a temperature lower than the predetermined temperature. 7. The bonding stage according to claim 6, wherein a heat block is provided below the stage plate, and the heat block is provided only below the bonding work area of the stage plate. Bump bonder. 8. The bump bonder according to claim 7, wherein a cutout is formed in the stage plate in at least a part of the non-work area adjacent to the bonding work area. 9. A bonding stage comprising a heat block disposed below a stage plate, wherein a control temperature of the heat block is set to a temperature suitable for a predetermined bonding operation in a lower portion of a bonding work area of the stage plate. The bump bonder according to claim 6, wherein a predetermined preheating temperature is set at a lower portion of the work area. 10. A bump bonder for forming a bump on a wafer supplied on a bonding stage by a bonding head and having a suction hole at a peripheral portion on the bonding stage for sucking a chip for the bonding. The bump bonder characterized by having arranged. 11. A bump forming method for forming a bump on a wafer supplied on a bonding stage by a bonding head, wherein a bump near a bonding head of the bonding stage is formed on a substantially half of the wafer as a bonding work area. Then, the wafer is turned over to form bumps in approximately the other half, and bumps are formed sequentially from the side away from the boundary between the bonding work area and the non-working area toward the side closer to the boundary when forming the bumps in the bonding work area. Forming a bump. 12. A bump forming method for forming bumps on a wafer supplied on a bonding stage by a bonding head, wherein the wafer is divided into blocks grouped into a plurality of IC chips and bumps are formed for each block. In addition, the inclination of the wafer required for correcting the bonding position data at that time is detected based on the inclination between the straight line connecting the centers of the IC chips corresponding to each other in the direction of the wafer reference line in the adjacent block and the reference line of the bonding stage. And correcting the position of the recognition window at the time of detecting the next inclination based on the detection result.