JP2003086611A - Ic die bonding device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve the problem that a device is enlarged since a wafer sheet fixing stand is made horizontal and it is disposed in an XY table for correcting the positions of individual chips although the size of a wafer becomes large for reducing a semiconductor manufacturing cost. SOLUTION: In a chip handling device, the chip is transported and bonded to a lead frame. A chip supply stand where a wafer sheet is fixed is almost vertically disposed. A chip suction head, which rotates at about 90 degrees and swing-transports the chip, transports the chip onto the lead frame in one unit.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improved IC die bonder.

[0002]

2. Description of the Related Art A die bonding process is one of semiconductor manufacturing processes. In this step, the chips formed by individually cutting the wafer set on the wafer sheet,
This is the step of adhering to the lead frame. As a conventional die bonding apparatus, a wafer sheet fixing base is provided on a rotary table and an XY table, the postures of the chips on the wafer sheet are adjusted in the XY directions and the inclinations, and then the chips are sucked one by one to be mounted on the lead frame. It is structured to be transported to.

A lead frame to which chips are temporarily adhered by a die bonding apparatus is housed in a case in units of several tens. Then, each case is sent to a separate heat curing furnace to perform main bonding.

[0004]

At present, the wafer size is increasing in order to reduce the semiconductor manufacturing cost. However, in the conventional die-bonding apparatus, since the wafer sheet fixing base is horizontally provided on the XY table for the purpose of correcting the position of each chip, the apparatus itself has to be upsized. However, the deterioration of space efficiency has become a problem.

Further, in order to prevent the occurrence of continuous defects such as scratches on the chip surface due to the adhesion of foreign matter to the tip of the chip suction head, conventionally, the suction head is regularly replaced and the product is inspected for inspection. However, in the sampling inspection, it is not possible to respond in real time, and many defective products may occur. For this reason, there are major problems in quality control, such as the necessity of increasing the number of sampling inspection steps and the loss of the suction head.

Further, conventionally, as a method of supplying a lead frame, a structure in which the next lead frame cannot be set unless the supplied lead frame is completely exhausted or the set position is divided into several positions,
There is a problem that work efficiency is reduced and the device is enlarged. Further, since the curing furnace for main bonding is a separate body, there are problems such as transportation from the die bonding apparatus and installation space.

In addition to this, there is a problem in accuracy of the lead frame feed position. Normally, the lead frame is transferred to the adhesive resin application position and the chip temporary adhesion position and stopped, but in the past,
This positioning is performed by the frame of the lead frame. For this reason, it is not possible to deal with the deformation of the lead frame and the like, which causes a defective product in which the chip bonding position is displaced.

[0008]

Therefore, the present inventor has achieved the present invention as a result of earnest research in view of the above problems, and is characterized in that in the IC manufacturing process,
A device for transporting and adhering chips formed by individually cutting a wafer set on a wafer sheet onto a lead frame, wherein a chip supply table for fixing the wafer sheet is provided substantially vertically, and Provided is a chip handling device for carrying the chips one by one onto the lead frame by a chip suction head which rotates by 90 degrees and swings and carries.

Alternatively, in the IC manufacturing process, a chip is formed by individually cutting a wafer set on a wafer sheet, and is a device for transporting and adhering the chip onto a lead frame, which is attached to a supply portion of the lead frame. A frame stopper that supports the lead frames is provided on the inner surface of the frame guide that receives the stacked lead frames that are lifted by the lifting lever.

Alternatively, in an IC manufacturing process, a chip formed by individually cutting a wafer set on a wafer sheet is transferred to and bonded to a lead frame, and the chip is temporarily bonded. The lead frame,
This is for hardening the thermosetting resin and making a permanent bond. It has a built-in layered thermosetting furnace that sequentially transfers it by an elevator and a conveyor.

Here, the "chip handling device" referred to in the present specification means that the chip suction head is approximately 90 ° on a vertical surface.
A device that conveys chips on a wafer sheet one by one onto a lead frame by rotating the wafer by one degree.
In the present invention, the chip supply table for fixing the wafer sheet is provided substantially vertically so that the chips on the wafer sheet can be conveyed to the lead frame in the horizontal state. Normally, the chip supply table is installed vertically, but ± 20
Within the range of °, the object of the present invention of downsizing the device can be achieved. Therefore, the rotation range of the chip suction head is 70 ° to 110 °.

In the present invention, the chip adsorbed from the wafer sheet by the chip handling device can be adhered onto the lead frame by correcting the center position and inclination of the chip during conveyance. To this end, a chip position measuring camera that measures the center coordinates and inclination of the chip is provided, and the chip handling device is provided in the attitude correction device, and the attitude of the chip is corrected based on the data detected by the camera.

The chip position measuring camera is provided at a position where an image of the chip being conveyed by the chip handling device is captured. In other words, it is a position where the chip sucked by the chip suction head is taken from the back side. Therefore,
The image is captured by the camera during the swing movement, and the processing time can be shortened. The chip and the reference spot are captured on the same screen as a method in which the deviation of the capture timing does not affect the measurement accuracy in capturing the image during the swing movement. Measuring the relative position of each central coordinate of the chip and the reference spot,
X due to the difference from the relative distance when the chip is not picked up
Calculate the Y deviation amount. As for the inclination of the chip, it is not affected by the fetching timing, so it is sufficient to simply measure the inclination of the chip image.

The XYθ correction amount is calculated based on the image data captured by the chip position measuring camera, and the attitude correction device controls the position of the chip handling device which swings by suctioning the chip. Therefore, since the posture is corrected during the swing movement, the processing time can be considerably shortened as compared with the conventional method in which the position is corrected and then the chip is sucked. Further, the image capturing by the chip position measuring camera can be used not only for the state of the chip but also for the purpose of managing the state of the tip end portion of the suction head such as adhesion of foreign matter to the suction head.

Further, by utilizing the chip handling device provided in the attitude correcting device, it is possible to correct the center position and the inclination of the chip during the chip transportation during the chip transportation, depending on the position of the lead frame to which the chip is bonded. Becomes For this purpose, a lead frame position measuring camera for measuring the position of the lead frame is provided. Based on the position and tilt data of the lead frame detected by this camera, the attitude correction device moves the chip handling device to correct the attitude of the chip. It is preferable to detect the position of the lead frame also at the position where the adhesive is applied to the lead frame, which is the stage before the chip temporary adhesion position.
As this method, for example, a lead frame position measuring camera is further provided in the adhesive application section, and X of the adhesive application head is used.
This is done by correcting the Y position.

The term "frame stopper" means that, when a plurality of stacked lead frames are fed to a frame supply section, they are provided on the inner surface of a frame guide arranged in the supply section to support the lead frames from below. Say. That is, the frame stopper is provided in a state of protruding at several places on the inner surface of the frame guide, and is supported and mounted when the number of lead frames becomes several. While supplying the lead frame supported and mounted by the frame stopper, the next bundle of lead frames can be prepared, and continuous frame supply becomes possible.

The "hierarchical thermosetting furnace" is a furnace for hardening a thermosetting resin and permanently adhering a lead frame to which chips are temporarily adhered, and horizontally moving a plurality of floors by a conveyor. , With a structure that allows elevators to move floors. By forming the heat curing furnace in a hierarchical structure, the inside of the furnace can be moved for the time required for the main bonding. Therefore, the main bonding can be continuously performed even in a narrow space, and the work efficiency can be improved by incorporating the main bonding in the IC die bonding apparatus.

Since this heat curing furnace is hierarchical, each floor may be provided with a blocking mechanism for preventing heat diffusion from other floors. This shut-off mechanism is intended to use the inside of the furnace as a temporary storage space by releasing the floor that has been emptied by passing the lead frame to be fully bonded to bring it to room temperature.

[0019]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described below in detail based on the embodiments of the invention shown in the drawings.

FIG. 1 shows an IC die bonder 1 according to the present invention.
The chip handling device 6 for vertically adhering the chip supply table 3 for fixing the wafer sheet 2 and adsorbing the chips 4 on the wafer sheet 2 and temporarily adhering them to the lead frame 5 is shown in FIG. Is provided. The wafer sheet 2 is an IC containing a plurality of containers.
It is loaded in the chip loading unit 7 under the front surface of the die bonding apparatus 1,
Each sheet 2 is vertically transferred from the bottom to the top and set on the chip supply table 3.

The chip handling device 6 is shown in FIG.
It is a device for swinging 90 ° from the chip supply table 3 provided vertically to the lead frame 5 in the horizontal position to convey the chips 4 and temporarily adhering them. Chip 4
Is sucked and conveyed by a chip suction head 62 provided at the tip of the swing head 61 of the chip handling device 6, but in order to accurately and temporarily adhere the chip 4 to the lead frame 5, the chip 4 in the suction state A camera 63 for measuring the position and the inclination is provided.

The camera 63 has a swing head 61 of 45
It is provided at a position (FIG. 3) where an image is taken in when it is rotated about a degree, and the chip 4 is sucked from the wafer sheet 2 of the chip supply table 3 to focus on the tip part of the chip suction head 62 during the swing movement to the lead frame 5. Are matched. In this example, the prism 63 is provided on the camera 63, the optical fiber 65 for the reference spot and the lens 66 for the small spot are provided on the swing head 61, and the focus of the reference spot is focused on the tip portion of the chip suction head 62. . On the monitor TV screen of FIG. 2B, the reference spot image is set as an absolute position, the relative distance between each center coordinate of the chip 4 is measured, and XY is obtained by the difference between the relative distance when the chip 4 is not sucked. Find the amount of deviation. Then, by simultaneously measuring the inclination of the chip 4, the XYθ correction amount for correction by the attitude correction device 8 is calculated.

The posture correction device 8 is operated in the XY direction as shown in FIG.
This is a structure in which a rotation correction table 82 for tilt correction is provided on the table 81. By providing the chip handling device 6 in the attitude correction device 8, an XY image is obtained by the image captured by the camera 63 of the chip 4 sucked from the wafer sheet 2.
The θ correction amount is calculated, corrected during the swing movement, and temporarily bonded onto the lead frame 5.

The function of the camera 63 may be to measure the position and inclination of the sucked chip 4 and also to manage the state of the chip suction head 62 as shown in FIG.
This monitor TV screen has chip 4 and lead frame 5
After temporarily adhering to the
It is an image captured by the camera 63 during the movement back in the direction, and shows a state in which a foreign matter is attached to the chip suction head 62. By detecting this, it is possible to prevent the occurrence of continuous defects by stopping the device as an abnormality.

FIG. 5A shows another example of the embodiment of the IC die bonding apparatus 1 according to the present invention, in which a frame stopper 52 is provided on the inner surface of a frame guide 51 for supplying the lead frame 5. It is a thing. When the lead frame 5 is supplied from one place, the frame stopper 52 enables continuous supply by placing several lead frames 5 on the frame.

As a method of supplying the lead frames 5, for example, about 100 lead frames 5 are set in the frame case 53. Then, after the frame case 53 moves to the rear frame take-out portion, the lead frame 5 set by the frame raising lever 54 is raised from below to the frame guide 51. The lead frames 5 sent to the frame guide 51 are taken out one by one by the suction pads for transportation and transported to the chip bonding position. Then, the emptied frame case 53 returns to the original position again and becomes ready for frame setting.

The raising lever 54 repeats the raising movement of the fine movement in response to the removal of the lead frame 5, but when the remaining lead frames 5 are few in number, they are placed on the frame stopper 52. I do.
This operation is performed by raising it by about 1 cm at a time and then lowering it to the lower end. Frame stopper 52
As long as it protrudes by about 5 mm, the lead frame 5 can be supported without dropping. By this operation, the remaining few lead frames 5 are placed on the frame stopper 52 as shown in FIG. 6B, and are sequentially sucked and transported by the transport suction pads. During this time, the frame case 53 accommodating the lead frame 5 is moved to the frame take-out portion and put on standby, whereby continuous supply becomes possible.

FIG. 6 shows an example of an embodiment of a layered thermosetting furnace 9, which is built in the IC die bonding apparatus 1 according to the present invention as shown in FIG. The lead frame 5 to which the chip 4 has been temporarily adhered is put into the thermosetting oven 9 while being housed in the case 91, and is permanently adhered. In this example, the case 91 accommodating the temporarily bonded lead frame 5 is sent to an elevator 92 arranged on the side of the thermosetting furnace 9, set on a conveyor 93 in the thermosetting furnace 9 and conveyed at a low speed. It In this way, the floors of the heat curing furnace 9 are moved by the left and right elevators 92 and the conveyor 93 for the time required to complete the main bonding, and then taken out from the heat curing furnace 9 and conveyed to the main bonding completed position.

When the IC die bonding apparatus 1 is stopped after the work is completed, the operator cannot leave the apparatus 1 until all the cases 91 in the thermosetting furnace 9 have been taken out. From this, by operating the work end switch, the power supply for the temporary adhesion is turned off, but the power supply for the thermosetting furnace 9 is not turned off until the main adhesion of all the cases 91 is completed.
In this case, a normal take-out operation is performed so that the case 91 that exceeds the main bonding time does not occur, but the space for the case 91 that is fully bonded is small due to space limitations.
There is a problem that can only be placed.

Therefore, in the present invention, the inside of the heat curing furnace 9 can be used as a temporary storage space 94.
In other words, each floor of the heat curing furnace 9 is provided with a shut-off mechanism for preventing heat diffusion from other floors, so that the floors that are emptied sequentially are brought to room temperature, so that all floors become temporary storage spaces 94. It is a structure.

The attitude correction of the chip 4 sucked by the chip suction head 62 is not only an absolute correction but also an absolute correction.
By correcting the position and inclination of the lead frame 5 to which the chip 4 is temporarily adhered, the chip 4 can be more accurately adhered. To correct the position and inclination of the lead frame 5, as shown in FIG. 7, a frame position measuring camera 56 is installed at the chip bonding position to measure the stop position of the lead frame 5, and the attitude correction device 8 is based on this data.
By moving the chip handling device 6. In this case, the correction operation by the posture correction device 8 is usually performed by the total correction amount of the position and inclination correction amount of the chip 4 and the position and inclination correction amount of the lead frame 5.

The roller feeding mechanism 55 of this embodiment is a mechanism for stopping the lead frame 5 at each of the adhesive resin application position and the chip temporary adhesion position. Lead frame 5
Are sent to the adhesive resin application position and the chip temporary adhesion position in pitch units by the NO1 and NO2 frame feed motors and the NO1 and NO2 frame stop sensors. In this case, when one lead frame 5 moves to both frame feed positions, the NO1 frame pressing roller rises and N is fed until the next lead frame 5 is fed.
Only the O2 frame feed section feeds the pitch. Further, in this example, the frame position measuring camera 5 is also installed at the adhesive resin application position.
6 is installed, the stop position of the lead frame 5 is measured, and the application position of the adhesive by the adhesive resin application head (not shown) is corrected.

[0033]

As described above, in the IC die bonding apparatus according to the present invention, in the IC manufacturing process, the chips formed by individually cutting the wafer set on the wafer sheet,
An apparatus for transferring and adhering onto a lead frame, in which a chip supply table for fixing the wafer sheet is provided substantially vertically, and the chips are picked up one by one by a chip suction head that rotates about 90 degrees and swings. By providing a chip handling device for carrying on the lead frame, it is possible to achieve a significant reduction in size and speed, improve productivity per unit area, and improve clean room management costs, and workers. By narrowing the work area, it is possible to obtain an effect such as an increase in the number of units managed by shortening the time required to move between devices.

Further, by providing the attitude correcting device with the chip handling device, it is possible to directly perform the position and inclination correction after the chip adsorption, so that the mechanical stress on the chip for the correction can be made zero. Adjustment such as alignment becomes extremely easy. In addition, the automatic management mechanism of the chip suction head also improves the quality control significantly, and the inspection man-hours can be significantly reduced.

Further, by providing a lead frame position measuring camera for measuring the position of the lead frame, the accuracy of the chip bonding position can be greatly improved. That is, by providing the chip handling device in the attitude correction device, the attitude of the chip can be simultaneously corrected not only with respect to the absolute position of the chip but also with respect to the position of the lead frame, and these correction operations can be performed instantaneously. be able to. For this reason, not only can the lead frame feed mechanism, which was complicated in order to increase the feed precision in the past, be simplified, but the precision of the chip bonding position can be substantially reduced without impairing workability as compared with the conventional one. It is possible to raise it.

Further, by providing a frame stopper on the inner surface of the frame guide provided in the lead frame supply section, it is possible to continuously supply the lead frame without loss time, and it is possible to perform stable and highly efficient device operation. Further, by incorporating a thermosetting furnace for main bonding in the apparatus main body, the construction period and the number of man-hours can be significantly improved, and automatic transfer to the wire bonding apparatus in the next step can be easily realized. In particular, by arranging the thermosetting ovens in layers, it is possible to make a space for temporarily placing the lead frame that is permanently bonded, and it is possible to effectively use the limited space.

[Brief description of drawings]

FIG. 1 is a perspective view showing an example of an embodiment of an IC die bonding apparatus according to the present invention.

FIG. 2A is a perspective view showing an example of an embodiment of a chip handling device, and FIG. 2B is an image for correcting the position and inclination of a chip taken in by a camera provided in the chip handling device.

FIG. 3 is a schematic side view showing an example of an embodiment of a posture correction device that corrects the position of a chip handling device that adsorbs a chip.

FIG. 4 is an image captured by a camera of a chip suction head of a chip handling device.

5A is a perspective view showing an example of an embodiment of a frame guide in a lead frame supply section, and FIG. 5B is a partially enlarged perspective view of FIG.

FIG. 6 is a schematic side view showing an example of an embodiment of a thermosetting furnace incorporated in the IC die bonding apparatus according to the present invention.

FIG. 7 is a schematic perspective view showing an example of an embodiment of a roller feed mechanism that feeds a lead frame to an adhesive resin application position and a chip temporary adhesion position in the IC die bonding apparatus according to the present invention.

[Explanation of symbols]

1 IC die bonder 2 wafer sheet 3 chip supply table 4 chips 5 lead frame 51 frame guide 52 frame stopper 53 frame cases 54 Lifting lever 55 Roller feed mechanism 56 frame position measurement camera 6 Chip handling equipment 61 swing head 62 chip suction head 63 chip position measurement camera 64 prism 65 optical fiber 66 Small Spot Lens 7 Chip input section 8 Posture correction device 81 XY table 82 Rotation correction table 9 heat curing furnace 91 elevator 92 conveyor 93 Temporary storage space

Claims (9)

[Claims] 1. A device for conveying and adhering chips formed by individually cutting a wafer set on a wafer sheet onto a lead frame in an IC manufacturing process, the chip fixing the wafer sheet. An IC die bonding apparatus characterized in that a supply table is provided substantially vertically, and a chip handling device that conveys the chips one by one onto the lead frame by a chip suction head that rotates about 90 degrees and swings. . 2. The IC die bonder according to claim 1, further comprising a chip position measuring camera for measuring center coordinates and inclination of a chip sucked by the chip suction head. 3. A chip handling device is provided in an attitude correction device that calculates the position and inclination of a chip sucked by a chip suction head from data detected by a chip position measurement camera and corrects the attitude of the chip. The IC die bonding apparatus according to claim 2, wherein 4. The chip position measuring camera acquires image data of the tip of the chip suction head.
The described IC die bonder. 5. The IC die bonding apparatus according to claim 1, further comprising a lead frame position measuring camera for measuring the position of the lead frame to which the chip is temporarily adhered. 6. The lead frame position and tilt are calculated from the data detected by the lead frame position measuring camera,
6. The IC die bonding apparatus according to claim 3, wherein the attitude of the chip suction head is corrected by the attitude correction device. 7. A device for transporting and bonding chips formed by individually cutting a wafer set on a wafer sheet to a lead frame and adhering the lead frame to the lead frame in an IC manufacturing process. What is provided is an IC die-bonding device, wherein a frame stopper that supports the lead frames is provided on an inner surface of a frame guide that receives the lead frames that are stacked up by a lifting lever. 8. A device for transporting and adhering chips formed by individually cutting a wafer set on a wafer sheet onto an lead frame in an IC manufacturing process, wherein the chips are temporarily adhered. An IC die-bonding device for curing the thermosetting resin for permanent bonding of the lead frame, and incorporating a hierarchical thermosetting furnace for sequentially transferring the lead frame by an elevator and a conveyor. 9. The IC die bonder according to claim 8, wherein the thermosetting oven is provided with a temporary storage space in which each floor is provided with a blocking mechanism for preventing heat diffusion from other floors.