KR101503556B1 - Method for picking up semiconductor chips from a wafer table and method for mounting semiconductor chips on a substrate - Google Patents

Abstract

The present invention relates to a method of picking up a semiconductor chip from a wafer table and, optionally, a method of mounting them on a substrate by a pick-and-place system. The position and orientation of the semiconductor chip to be mounted next is determined by the first camera and is available in the form of position data relating to the first coordinate system. The position and orientation of the substrate location on which the semiconductor chip is to be mounted is determined by the second camera and is available in the form of position data relating to the second coordinate system. The transformation of the coordinates of the first or second coordinate system to the coordinates of the motion of the pick-and-place system is performed by two fixed mapping functions and two variable calibration vectors. The calibration vector is readjusted when a given event (event) occurs.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a method of picking up a semiconductor chip from a wafer table and a method of mounting the semiconductor chip on a substrate.

The present invention relates to a method of the type mentioned in the preamble of claim 1 for picking up a semiconductor chip provided on a wafer table. The present invention also relates to a method for mounting a shifted semiconductor chip on a substrate.

A mounting machine for mounting a semiconductor chip is known in the art as a die bonder. The mounting machine is used to mount a number of uniform chips of a wafer located next to each other on a chip carrier onto a substrate, for example, a metal lead frame. The die bonder includes a wafer table on which the chip carrier is located, a transfer system for supplying the substrate, and a pick-and-place system for transferring the semiconductor chips from the chip carrier and placing them on the substrate . The pick-and-place system includes a bonding head with a chip gripper moving back and forth by the drive system. The chip gripper can rotate about a vertical axis, so that the turning point of the semiconductor chip can be changed if necessary. The chip gripper includes a replaceable gripping member, which is a suction member to which a vacuum can be applied, which in the art is referred to as a "pick-up tool" or a "die collet ).

Extremely high requirements exist for this type of mounting machine. They need to be placed in the correct position on the substrate for further processing of the mounted chip. Two cameras are provided in the die bonder to ensure that the semiconductor chip can be placed on the substrate with an accuracy that lies within the micrometer range. The first camera measures the position of the semiconductor chip to be picked up by the chip gripper, and provides position data on the first coordinate system. The second camera measures the position of the substrate place where the semiconductor chip needs to be placed and provides position data about the second coordinate system. The pick-and-place system controls the bonding head based on the information provided by the camera so that the chip gripper can move the semiconductor chip from the wafer table and place it precisely in a proper location on the substrate site. The location of the pick-and-place system is related to a third coordinate system that is independent of the camera's coordinate system.

There arises a problem that, during operation of the die bonder, the relative positions of the three coordinate systems may vary due to different conditions. Intentionally or unintentionally, the temperatures at the different locations of the die bonder often change. This results in the most inaccurate result as it is no longer necessary to convert the target coordinates determined in the first camera's coordinate system or the second camera's coordinate system to the motion coordinates for the pick-and-place system.

The present invention is based on the object of providing a method of picking up and mounting a semiconductor chip that ensures a high accuracy placement regardless of the external environment and variations. This object is achieved according to the invention by the features of claim 1.

The present invention provides a method for picking up a semiconductor chip and optionally mounting it on a substrate,

A semiconductor chip is provided on the wafer table;

The substrate being provided in turn on the substrate table;

The first camera is provided on the wafer table and then detects the position and orientation of the semiconductor chip to be mounted;

- the second camera detects the position and orientation of the substrate location on which the semiconductor chip is to be mounted; And

The chip gripper picks up the semiconductor chip provided on the wafer table and mounts it on the substrate, the chip gripper is held in the bonding head, and the pick-and-place system, preferably with two linear drivers, The bonding head is transferred between the wafer table and the substrate back and forth.

According to the present invention, the position of the next semiconductor chip to be mounted, which is detected by the first camera, is provided in the form of position data relating to the first coordinate system KS ₁ , ₂ , and the position of the bonding head is related to the third coordinate system KS ₃ .

The present invention proposes to provide a marking to the bonding head whose position can be measured by a camera. Since the marking can not be placed in the focal plane of the camera for structural reasons, the present invention further proposes attaching a lens over the marking in a preferred embodiment, said lens being characterized in that the marking is also in a very distinct manner Lt; / RTI >

The present invention further includes a first fixed mapping function F and a first changeable correction function F to transform the coordinates of the first coordinate system KS ₁ into a third coordinate system KS ₃ of the pick- using the vector) K _1, and the coordinates pick of the second coordinate system KS _2-and-place system, a third coordinate system, using a second fixed mapping function G with a second changeable correction vector K ₂ in order to convert the KS ₃ in Lt; / RTI > When the die bonder is initially set, or in the case of a general new setting of the die bonder, on the one hand the mapping functions F and G and their inverse functions are determined and the two calibration vectors K ₁ and K ₂ are set to zero. The calibration functions K ₁ and K ₂ are readjusted when a given event (event) occurs, while the mapping functions F and G are not changed until the next general new setting of the die bonder. The predetermined event can be understood as an event (event) which can be expected to have a high possibility that the relative positions of the three coordinate systems KS ₁ , KS ₂ , KS ₃ are changed relative to each other such that the position accuracy is reduced have.

The present invention has an effect of providing a method of picking up and mounting a semiconductor chip that ensures a high accuracy placement regardless of external environment and change.

BRIEF DESCRIPTION OF THE DRAWINGS The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate one or more embodiments of the invention and, together with the description, serve to explain the principles and implementations of the invention. The drawings are not exhaustive.
1 shows a top view of a mounting machine for mounting a semiconductor chip;
Figure 2 shows a side view of the camera, bonding head and wafer table, and
Figure 3 shows a top view of the bonding head and three different coordinate systems.

Fig. 1 schematically shows a plan view of a so-called die bonder, which is a mounting machine for mounting a semiconductor chip, to the extent necessary for the understanding of the present invention. Figure 2 shows parts of a mounting machine in side view. The die bonder comprises a wafer table 1 provided with a semiconductor chip 2 to be mounted thereon, a substrate table 3 provided with a transfer device (not shown), and a wafer table 3 A pick-and-place system 5 for picking up the semiconductor chip 2 from the substrate 1 and placing it on the substrate 4, and two cameras 6 and 7. The pick-and-place system 5 includes a bonding head 8 having a replaceable chip gripper 9 (Fig. 2), and bonding heads 8 in two orthogonal directions designated in the x- and y- And two linear, position-controlled drives for moving the wheels. A third drive (not shown) is used to raise and lower the bonding head 8 or the chip gripper 9 in the z-direction extending perpendicularly to the view plane. The first camera 6 is used to determine the position of the next semiconductor chip 2 to be moved. The second camera 7 is used to determine the position of the substrate place on the substrate 4 on which the semiconductor chip 2 is to be placed. The first camera 6 is generally arranged in a fixed manner. The second camera 7 can also be moved in a fixed manner or in a separate driving device in at least one or two directions extending parallel to the surface of the substrate 4. [ Such a pick-and-place system 5 is known, for example, from EP 923,111, EP 1,480,507, DE 102004026534 and EP 1,612,843.

The marking 10 (Fig. 2) is used to allow the bonding head 8 to be visible in the image provided by the first camera 6 when the bonding head 8 is positioned in the field of view of the first camera 6, When the second camera 7 is positioned in the field of view of the second camera 7, it is laterally attached to the bonding head 8 so that it can be seen in the image provided by the second camera 7.

Fig. 2 shows a side view of the first camera 6, the bonding head 8 and the wafer table 1. Fig. Its field of view defined by the lines 6a in the figure is directed towards the wafer table 1 and the next semiconductor chip 2 to be moved in the image provided thereby is very clearly imaged. The focal plane of the first camera 6 lies in a plane defined by the semiconductor chip 2 to be moved. The focal plane of the second camera 7 (Fig. 1) lies in a plane defined by the plane of the substrate 4 to be mounted. Without the adjustment of the focal plane, it is impossible to attach the marking 10 to the bonding head 8 so as to be imaged very clearly by both cameras 6, To ensure that the marking 10 is imaged in a very distinct manner, advantageously the lens 11 is attached to the bonding head 8 above the marking 10. The lens 11 is located between the marking 10 and each of the cameras 6 and 7 and ensures that the marking 10 is imaged in a clear and clearly defined manner to the image of each camera 6,7 . It may also be expected to adjust the focus plane of the camera instead of providing the lens 11 to ensure that the marking 10 is imaged in a clearly defined manner. Since a smaller adjustment range of the lens system of the resultant camera 6, 7 of the lens 11 is required, the solution by the lens 11 is simpler, faster, and more cost-effective.

The first camera 6 supplies its image data to the first image processing unit which determines the position and orientation of the semiconductor chip 2 to be mounted next from the image data and sets them as position data on the first coordinate system KS ₁ . The two numbers p and q designate the position of the reference point of the semiconductor chip 2 and the number? Designates the position of the semiconductor chip 2 in its setting (p, q, Determines the angle of rotation with respect to the setpoint position.

The second camera 7 is located on the supply of its image data to the second image processing unit for determining the position and orientation of the substrate location where the semiconductor chip 2 is attached from the image data, and those in the second coordinate system KS ₂ Provided in the form of data. These position data are composed of three numbers (u, v, ψ), numbers u and v indicate the position of the reference point at the position of the substrate place, and number ψ is the position Displays the angle.

The first linear driver of the pick-and-place system supplies a number x _M and the second linear driver of the pick-and-place system supplies the number y _M , which together with the markings on the third coordinate system KS ₃ (X _M , y _M ) of the display unit 10 is formed.

The chip gripper 9 can rotate around a rotational axis 12 (Fig. 2). The suction opening of the chip gripper 9 defines the position of the gripper shaft 13 (Fig. 2) of the chip gripper 9. The position (x _G , y _G ) of the gripper shaft 13 of the third coordinate system KS ₃ ,

_{(x G, y G) =} (x M, y M) + D + E

Lt; / RTI >

Where vector D represents the position of the rotary axis 12 with respect to the position (x _M , y _M ) of the marking 10 and vector E represents the position of the gripper axis 13 with respect to the position of the rotary axis 12 . The vector D is a fixed vector to be determined once. Vector E is a vector that rotates with the chip gripper 9: its length has a fixed amount, but its direction changes as the chip gripper 9 rotates about the rotational axis 12. In the ideal case, the rotary shaft 12 and the gripper shaft 13 always coincide irrespective of the rotational position of the chip gripper 9, that is, E = 0.

Figure 3 shows the correlation between the three coordinate systems KS ₁ , KS ₂ and KS ₃ . In order to ensure that the semiconductor chip 2 can be placed on the substrate 4 in a precisely positioned manner, it is necessary to have a first coordinate system KS ₁ and a second coordinate system KS ₂ Be able to calculate the current position of the gripper shaft 13 of the chip gripper 9 in both. Thus, the first mapping function F is determined in the initial setup of the mounting machine or in the general new setting, and the function F maps the first coordinate system KS ₁ to the third coordinate system KS ₃ . This is accomplished with the aid of the marking 10: the two linear drivers of the pick-and-place system 5 allow the bonding head 8 with the markings 10 to move within the field of view of the first camera 6 from n = 1 to k in k different locations and go to (x _n, y _n), the first image processing unit is related to the position of the marking 10 from the image supplied by the first camera (6) (p _n , q _n ). The first mapping function F is calculated from the obtained data record. Then the following applies:

(x, y) = F (p, q)

The inverse F ^-1 of the mapping function F is then calculated,

(p, q) = F ^-1 (x, y)

Also, the first calibration vector K ₁ is set to the value K ₁ = 0.

Similarly, a second mapping function G for mapping the second coordinate system KS ₂ to the third coordinate system KS ₃ and its inverse function G ^-1 is determined. Then the following applies:

(x, y) = G (u, v)

And vice versa

(u, v) = G ^-1 (x, y)

Also, the second calibration vector K ₂ is set to the value K ₂ = 0.

The first camera 6 and the first coordinate system KS ₁ are used to determine the target coordinates for the first coordinate system KS ₁ , where the pick-and-place system 5 should move the bonding head 8 there, The chip gripper 9 can pick up the semiconductor chip 2 provided on the wafer table 1. [ The second camera 7 and the second coordinate system KS ₂ is a pick-be used to determine the target coordinates in the second coordinate system to place the system 5 need to move the bonding head 8 there KS _2, - and The chip gripper 9 can place the semiconductor chip 2 in a precisely positioned manner. All calculations are performed in these two coordinate systems KS ₁ and KS ₂ . After all calculations are complete, the determined target coordinates will be transformed by the respective mapping functions F and G into the coordinates of the motion of the third coordinate system KS ₃ . Therefore, vectors D and E are determined in accordance with both vectors D ₁ and E ₁ relating to the first coordinate system KS ₁ and vectors D ₂ and E ₂ relating to the second coordinate system KS ₂ . Therefore, the third coordinate system KS ₃ is used only to move the bonding head 8 without performing any calculation in this coordinate system KS ₃ . The third coordinate system KS ₃ is given by the mechanism of the pick-and-place system 5, i.e. the coordinates x and y are position values supplied by the encoders of the two linear actuators, .

Once the mapping functions F and G, their inverse functions F ^-1 and G ^-1 , and the vectors D ₁ , E ₁ , D ₂ and E ₂ are determined, the semiconductor chip 2 can be successively mounted on the manufacturing stage

The image of the next semiconductor chip 2 is photographed by the first camera 6 and the position data (p _w , q _w , φ _w ) concerning the first coordinate system KS ₁ of the semiconductor chip 2 is calculated from the image Where φ _W = 0 when the semiconductor chip 2 does not rotate with respect to its set point position;

(X _W , y _W) related to the third coordinate system KS ₃ that need to be obtained by the marking 10 so that the gripper shaft 13 of the chip gripper 9 passes past the reference point of the semiconductor chip 2. [ ) Is calculated as follows;

(x _W , y _W ) = F [(p _W , q _W ) - D ₁ - E ₁ + K ₁ ]

- the calculated position (x _W , y _W ) approaches and the semiconductor chip 2 is picked up by the chip gripper 9;

The image of the substrate place on which the semiconductor chip 2 is to be mounted is photographed by the second camera 7 and the position data u _S , v _S , ψ _S of the substrate position with respect to the second coordinate system KS ₂ is obtained from the image Where ψ _S = 0 when the substrate position is not rotated with respect to its set point position;

The position (x _S , y _S ) related to the third coordinate system KS ₃ , which is required to be obtained by the marking 10, is set so that the gripping axis 13 of the chip gripper 9 passes past the reference point of the substrate position, Lt; / RTI >

(x _S , y _S ) = G [(u _S , v _S ) - D ₂ - E ₂ + K ₂ ]

The calculated position (x _S , y _S ) is approaching and the chip gripper 9 is optionally rotated by a weak angle ψ _S - φ _S , and the semiconductor chip 2 is placed in the substrate place.

In order to maintain the placement accuracy of the die bonder at the same high level during the whole fabrication, readjustment of the first calibration vector K ₁ and the second calibration vector K ₂ is performed during the occurrence of the predetermined event (event). The marking 10 provided on the bonding head 8 is used and the marking is placed into the field of view of the first camera 6 for readjustment of the first calibration vector K _{1 and} the readjustment of the second calibration vector K ₂ In the field of view of the second camera 7. Recalibration of the first calibration vector K ₁ occurs by the following steps:

Moving the bonding head 8 to a set point position R = (x _R , y _R ) where the marking 10 is located within the field of view of the first camera 6, wherein the coordinates (x _R , y _R ) Is associated with the third coordinate system KS ₃ .

calculating a set point position (p _R , q _R ) of the marking (10) with respect to the first coordinate system KS ₁ according to (p _R , q _R ) = F ^-1 (x _R , y _R );

- photographing the image of the marking (10) with the first camera (6), - determining the actual position (p _M , q _M ) of the marking (10) with respect to the first coordinate system KS ₁ , ≪ / RTI >

Calculating a first calibration vector K ₁ in accordance with a difference between a setpoint position close to the measured position and the measured actual position;

K ₁ = (p _R , q _R ) - (p _M , q _M ).

It is obvious that the first calibration vector K ₁ is associated with the first coordinate system KS ₁ .

The readjustment of the second calibration vector K ₂ similarly occurs by the following steps:

Moving the bonding head 8 to a set point position T = (x _T , y _T ) where the marking 10 is located in the field of view of the second camera 7, wherein the coordinates (x _T , y _T ) Is associated with the third coordinate system KS ₃ ;

calculating a set point position (u _T , v _T ) of the marking (10) with respect to the second coordinate system KS ₂ according to - (u _T , v _T ) = G ^-1 (x _T , y _T );

- photographing the image of the marking (10) with the second camera (7), determining the actual position (u _M , v _M ) of the marking (10) with respect to the second coordinate system KS ₂ ;

Calculating a second calibration vector K ₂ according to the difference between the set point position proximate and the measured actual position:

K ₂ = (u _T , v _T ) - (u _M , v _M ).

It is clear that the second calibration vector K ₂ is associated with the second coordinate system KS ₂ .

There are different events (events) that can trigger the readjustment of the calibration vectors K ₁ and K ₂ , in particular the following four events:

After the final correction, a predetermined number of semiconductor chips 2 are mounted;

After the final correction, the measured temperature at a predetermined position of the pick-and-place system 5 is changed by a predetermined value or more;

- production ceases;

The actual position of the mounted semiconductor chip detected and calculated by the second camera 7 after mounting is shifted by a predetermined amount or more from the set point position.

After the completion of the rebalancing of the calibration vectors K ₁ and K ₂ , the mounting of the semiconductor chip 2 may continue according to the steps described above, but the updated calibration vectors K ₁ and K ₂ may be different from zero at present.

The present invention relates to a platform 3 for a substrate 4 and a known pick-and-place system in which the wafer table 1 is arranged in a parallel plane, as well as a platform 3 for a substrate, In the case of the pick-and-place method described in European Patent EP 1,480,507 in which the table 1 is disposed in an inclined manner with respect to each other and the bonding head 8 performs a movement about the horizontal axis in addition to the movement in the x- and y- It can also be applied to an ' -place system.

In the above-described embodiment, the bonding head moves to the first set point position R and the second set point position T, respectively, for adjustment and re-adjustment, and the first set point position R and the second set point R about the third coordinate system KS ₃ Is the preferred embodiment in which the coordinates of the position T are stored and used to readjust the two calibration vectors K ₁ and K ₂ . In this embodiment, each set point position of the marking 10 is calculated by the inverse functions F ^-1 and G ^-1 , respectively. When the bonding head 8 is located at the first or second set point position, the coordinates of the marking 10 with respect to the first coordinate system KS ₁ (or any other arbitrary reference point of the bonding head 8) Additional embodiments in which the coordinates of the marking 10 with respect to KS ₂ (or any other reference point of the bonding head 8) are additionally stored and which are then used for readjustment of the two calibration vectors K ₁ and K ₂ , .

The pick-and-place system includes as a part a pick system for picking up a semiconductor chip from the wafer table. The third coordinate system KS ₃ is a coordinate system inherent in the pick system or the pick-and-place system, and will be referred to hereinafter as the coordinate system KS. Adjustment is first performed in a setup phase in which the bonding head 8 moves to a first set point position located in the field of view of the first camera 6, (P _SP1 , q _SP1 ) of the first set point position with respect to the coordinate system KS ₁ of the first camera 6 and the coordinates (x _SP1 , y _SP1 ) of the first set point position with respect to the first camera 6 are determined and stored. The re-adjustment takes place at the manufacturing stage so that the bonding head 8 is moved to the coordinates (x _SP1 , y _SP1 ) of the first set point position and the coordinates p (x _SP1 , y _SP1 ) of the set point position with respect to the coordinate system KS ₁ of the first camera 6 _SP1 ', q _SP1 ') is determined again. The difference vector (p _SP1 ', q _SP1 ') - (p _SP1 , q _SP1 ) contains information about the displacement of the first coordinate system KS ₁ with respect to the coordinate system KS generated after the setting. Any arbitrary reference point of the bonding head 8 can be used for defining the first set point position of the bonding head 8 with respect to the first coordinate system KS ₁ . Preferably, the above-mentioned marking 10 is used for limiting the reference point.

In a similar manner, the displacement of the second coordinate system KS ₂ of the second camera 7 is detected and corrected with respect to the coordinate system KS of the bonding head 8, so that the second set point position (X _SP2 , y _SP2 ) of the second set point position with respect to the coordinate system KS and the coordinate system KS ₂ of the second camera 7 with respect to the coordinate system KS, 2 The coordinates (u _SP2 , v _SP2 ) of the set point position are determined and stored. The bonding head 8 is moved to the coordinates (x _SP2 , y _SP2 ) of the second set point position and the coordinates of the second set point position related to the coordinate system KS ₂ of the second camera 7 (u _SP2 ', v _SP2 ') is again determined. The difference vector u _SP2 ', v _SP2 ' - (u _SP2 , v _SP2 ) contains information about the displacement of the second coordinate system KS ₂ with respect to the coordinate system KS generated after the setting of the setting step. Even in this case, any arbitrary reference point on the bonding head 8 can be used for defining the second set point position of the bonding head 8 with respect to the second coordinate system KS ₂ . Preferably, the marking 10 as mentioned above is used for the limitation of the reference point.

The determination of the coordinates of the reference point with respect to the first coordinate system KS ₁ and the second coordinate system KS ₂ involves taking an image with each camera 6, 7 and determining the coordinates of the reference point by conventional image evaluation .

Then the mounting of the semiconductor chip preferably takes place as follows:

The position of the semiconductor chip 2 to be mounted next, which is detected by the first camera 6, is provided in the form of position data relating to the first coordinate system KS ₁ ;

The position of the substrate place on which the semiconductor chip 2 is to be mounted, which is detected by the second camera 7, is provided in the form of position data relating to the second coordinate system KS ₂ ;

In the set-up step, the first mapping function for mapping the first coordinate system KS ₁ to the coordinate system KS and its inverse function are determined, the first calibration vector is set to the value zero, the second coordinate system KS _{2 is set} to the coordinate system KS The inverse function thereof is determined, and the second calibration vector is set to the value zero.

- the semiconductor chip (2) is in turn mounted in the manufacturing step;

The image of the semiconductor chip 2 to be mounted next is photographed by the camera 6 and the position of the semiconductor chip 2 with respect to the first coordinate system KS ₁ is determined, - the position with respect to the coordinate system KS in which the ' -position system 5 needs to move the bonding head 8 is calculated therefrom by means of a first mapping function and by taking into account the first calibration vector;

The image of the substrate location on which the semiconductor chip 2 is to be mounted is photographed by the second camera 7 and the position of the substrate location relative to the second coordinate system KS ₂ is determined and the semiconductor chip 2 is mounted The position with respect to the coordinate system KS in which the pick-and-place system 5 needs to move the bonding head 8 is calculated therefrom by considering the second calibration vector and by the second mapping function;

And the readjustment of the fabrication step includes readjustment of the first and second calibration vectors and has the following steps:

- moving the bonding head (8) to a first set point position;

- photographing the image of the marking (10) with the first camera (6) and determining the actual position of the marking (10) with respect to the first coordinate system KS ₁ from the image of the first camera (6);

Calculating a first calibration vector K ₁ as a difference between the stored set point position and the determined actual position;

- moving the bonding head (8) to a second set point position;

- photographing the image of the marking (10) with the second camera (7) and determining the actual position of the marking (10) with respect to the second coordinate system KS ₂ from the image of the second camera (7); And

Calculating a second calibration vector K ₂ as a difference between the stored set point position and the determined actual position;

Although the embodiments and applications of the present invention have been shown and described, those skilled in the art, having the benefit of this disclosure, will appreciate that many more modifications than mentioned above are possible without departing from the spirit of the present disclosure. Accordingly, the invention is not limited except as by the appended claims and their equivalents.

1: Wafer table
2: Semiconductor chip
3: substrate table
4: substrate
5: Pick-and-Place System
6: First camera
6a: line
7: Second camera
8: Bonding head
9: chip gripper
10: Marking
11: Lens
12: Rotation axis
13: Gripper shaft

Claims (8)

A method of mounting a semiconductor chip (2) provided on a wafer table (1) by a pick-and-place system (5) with a bonding head (8) to a substrate (4) 8, and in this way
The image of the semiconductor chip 2 provided in the wafer table 1 is photographed by the first camera 6 and the position of the semiconductor chip 2 determined from the image is provided in the form of position data relating to the first coordinate system KS ₁ And,
The image of the substrate location is photographed by the second camera 7 and the position of the substrate location determined from the image is provided in the form of positional data relating to the second coordinate system KS ₂ ,
The position of the bonding head 8 is related to a third coordinate system KS ₃ inherent in the pick-and-place system 5, the method comprising a setting step and a manufacturing step,
Wherein the setting step comprises the following steps:
Determining a first mapping function and an inverse function thereof to map the first coordinate system (KS ₁ ) to the third coordinate system (KS ₃ )
Setting a first calibration vector to a value of zero,
Determining a second mapping function for mapping the second coordinate system (KS ₂ ) to a third coordinate system (KS ₃ ) and its inverse function, and
Setting a second calibration vector to a value of zero; And
The manufacturing step comprises the following steps:
In the step of sequentially mounting the semiconductor chips 2,
Taking an image of the semiconductor chip 2 to be mounted next with the first camera 6,
Determining the position of the semiconductor chip 2 with respect to the first coordinate system KS ₁ from the image of the first camera 6,
In order to pick up the semiconductor chip 2 and the pick-and-place system (5) by the position on the third coordinate system (KS ₃₎ in which there is a necessity to move the bonding head 8 to the first mapping function and the first Calculating by considering a calibration vector;
Photographing the image of the substrate place where the semiconductor chip 2 is to be mounted with the second camera 7,
Determining the position of the substrate location relative to the second coordinate system (KS ₂ ) from the image of the second camera (7), and
In order to mount the semiconductor chip 2 to a substrate place the pick-and-place system (5) by a second mapping function, the position on the third coordinate system (KS ₃₎ which is required to move the bonding head 8 And by considering a second calibration vector; And
And re-calibrating the first and second calibration vectors at the occurrence of a predetermined event, wherein the re-calibration of the first and second calibration vectors comprises the following steps:
Moving the bonding head (8) to a first set point position where the marking (10) is located within the field of view of the first camera (6)
Calculating a first set point position of the marking (10) with respect to the first coordinate system (KS ₁ )
Photographing the image of the marking 10 with the first camera 6,
Determining the actual position of the marking (10) with respect to the first coordinate system (KS ₁ ) from the image of the first camera (6)
Calculating a first calibration vector K ₁ as a difference between the calculated set point position of the marking 10 and the determined actual position;
Moving the bonding head (8) to a second set point position where the marking (10) is located within the field of view of the second camera (7)
Calculating a second set point position of the marking (10) with respect to the second coordinate system (KS ₂ );
Photographing the image of the marking 10 with the second camera 7,
Determining an actual position of the marking (10) with respect to the second coordinate system (KS ₂ ) from the image of the second camera (7), and
Calculating a second calibration vector as a difference between the calculated set point position of the marking (10) and the determined actual position
And mounting the semiconductor chip on the semiconductor chip. The method according to claim 1,
Wherein the predetermined event is at least one of the following events:
An event in which a predetermined number of semiconductor chips 2 are mounted after the final correction;
An event in which the measured temperature at a predetermined position of the pick-and-place system 5 after the final correction is changed by a predetermined value or more;
- an event where manufacturing ceases;
- an event in which the actual position of the mounted semiconductor chip detected and calculated by the second camera (7) after mounting deviates by more than a predetermined amount from the set point position. The method according to claim 1,
Characterized in that the marking (10) applied to the bonding head (8) is imaged onto each camera (6 and 7) by a lens (11) attached to the bonding head (8). 3. The method of claim 2,
Characterized in that the marking (10) applied to the bonding head (8) is imaged onto each camera (6 and 7) by a lens (11) attached to the bonding head (8). 5. The method according to any one of claims 1 to 4,
The step of determining the first mapping function comprises moving the bonding head 8 to several different positions so that the marking 10 is located within the field of view of the first camera 6, Wherein the step of determining the second mapping function comprises the step of photographing the image and determining the relative position of the marking (10) from the image provided by the first camera (6) Moving the bonding head 8 to several different positions so as to be positioned within the field of view of the first camera 7, taking an image with the second camera 7, (10) of the semiconductor chip (10). delete delete delete

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