JPS6328765B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to a dicing apparatus equipped with an automatic handling mechanism, and particularly to a dicing apparatus for semiconductor wafers.

For example, the basic configuration of a dicing apparatus is disclosed in Japanese Patent Application Laid-Open No. 51-28754.

[Prior art]

In manufacturing semiconductor elements such as transistors and semiconductor integrated circuits (ICs), the process begins with preparing ingot-shaped single crystal semiconductor materials and cutting these semiconductor ingots into a number of semiconductor wafers. The cutting operation of the semiconductor ingot is generally known as slicing, and the semiconductor ingot is cut with a diamond cutter or the like.

The semiconductor wafer thus obtained is then sent to various steps such as oxidation, diffusion, and vapor deposition, and a large number of semiconductor element regions are formed within the semiconductor wafer.

In order to individually separate the large number of semiconductor elements formed within the semiconductor wafer, the semiconductor wafer is then subjected to a dicing operation, and a large number of vertical and horizontal grooves are formed on the wafer surface so as to surround each element. Next, the wafer is subjected to a breaking operation, and the wafer is divided into a number of semiconductor pellets (dies or chips) by breaking the wafer along the dicing grooves. These pellets are then sorted and classified according to their characteristics, and then each pellet is brazed onto a support such as a lead frame or stem, followed by wire bonding and encapsulation to form semiconductor devices. It is assembled as.

By the way, in the above-mentioned series of manufacturing processes, the dicing work is a work to separate a large number of semiconductor pellets from a single semiconductor wafer on which a large number of semiconductor elements are formed, so the work can be done quickly and efficiently. It needs to be done efficiently.

FIG. 1 shows a series of conventional dicing operations in order of process. First, as shown in A, case 2 stores a large number of wafers 1 to be diced.
Next, as shown in B, pick up the wafers 1 one by one from the case 2 with the tweezers 3, place them on the dicing table 4, and position them.
Perform the original dicing work using the dicing blade 5 as shown in C. Next, as shown in D, the wafer 1 that has been diced is transferred from the table 4 by the tweezers 2, and then transferred to the case 2 again as shown in E.
stored inside.

However, the conventional dicing operation was inefficient because more time was spent on preparatory work related to the steps before and after the dicing operation than the time required for the actual dicing operation itself.

In other words, since all wafer handling work before and after dicing is done manually, and because it takes time to position (align) the wafer to be diced on a predetermined table, it is difficult to start the original dicing process. The number did not increase.

In addition, since handling such as setting and removing the wafer from the dicing table is done manually, the method and strength of the mechanical external force applied to the wafer becomes unstable, resulting in mechanical damage to the wafer. was inevitable.

According to studies conducted by the present inventors, if the loader and unloader are laid out on both sides of the blade, one loader section will move in the direction of the lower end of the blade, so water droplets and cutting chips will scatter on that loader section. It was found that the wafers, jigs, etc. could be contaminated.

The present invention has been made to solve such problems, and its gist is to provide a loader device for supplying wafers to a dicing device, and a loader device provided adjacent to the loader device to store wafers after dicing. a first transfer device that transfers the wafer unloaded from the loader device onto a dicing table; a wafer positioning device that positions the wafer transferred onto the dicing table; and a wafer positioning device that rotates the positioned wafer. A dicing device that performs dicing using a blade;
A location where the dicing table on which the wafer transferred by the first transfer device is placed is moved to the wafer positioning device and the dicing device, and the wafer is transferred from the dicing device by the first transfer device. a dicing table moving mechanism that returns the dicing table until the dicing table is reached; a second transfer device that transfers the wafer diced by the dicing device to another table separate from the dicing table; and a wafer transferred to the other table. A cleaning device that spins and cleans the
a third transfer device that transfers the wafer on the other table to a wafer loading device for the unloader device;
The automatic dicing apparatus is characterized in that the automatic dicing apparatus is disposed at a location away from the conveyance path of each of the first to third conveyance apparatuses and far from the loader apparatus and the unloader apparatus.

〔Example〕

In the following, an automatic dicing apparatus developed by the inventor for the first time will be described as an example.

Embodiments of the present invention will be described below with reference to the drawings. In FIG. 2, a dicing apparatus (hereinafter referred to as the apparatus) is composed of a wafer loader apparatus A, a wafer positioning apparatus B, a wafer alignment apparatus, a dicing apparatus C, a wafer cleaning apparatus D, a wafer unloader apparatus E, a wafer chuck apparatus F, and the like. Particularly important in the above configuration is the wafer chuck device F, and the chuck mechanism is a so-called perny chuck that uses fluid (air, etc.) and buoyancy when sprayed onto the object to be processed.
Handling work when transferring a wafer between each component is performed using this chuck without directly touching the object to be processed.

Each component will be explained in detail below. FIG. 3 shows a wafer loader section, in which a cartridge 6 containing a certain number of wafers 1 (for example, about 20 to 25) to be diced is set at a predetermined position 7 of the apparatus. An air chute 8 is provided at this position 7, and when the wafer 1 is placed (supplied) from the cartridge 6 onto the end of the air chute 8, the wafer 1 is immediately exposed to the air indicated by the arrow on the air chute 8. It is transferred in the direction of spraying. The cartridge 6 is filled with wafers that are regularly arranged in a vertical line, for example, and the wafers at the bottom of the cartridges (the wafers placed on the air chute) are particularly exposed to light emitted from the light source 9. Light is placed in the beam path leading to phototransistor 10. The output signal of the phototransistor 10 is transmitted to the motor 11, and the operation of the motor 11 is controlled according to this output signal. For example, if the wafer is in the above path as shown in B (the state where the light beam is completely blocked),
A "wafer present" signal is transmitted from the phototransistor 10 to the motor 11, and the motor 11 does not operate at this time. However, when the wafer is transferred onto the air chute in the next instant as shown in A, the light beam path becomes conductive, and the phototransistor 10 sends a "no wafer" signal to the motor 11.
At this time, the motor 11 operates to lower the wafers 1 in the cartridge 6 one pitch at a time. Figures C and D show other examples of wafer detection methods; C is a method of detecting from the rear of the cartridge 6, and D is a method of detecting from the rear of the cartridge 6, and D is a method in which another detection means is added to the back side of the air chute in addition to the method of C above. This shows the configuration. In method D, if a wafer is caught at the air chute entrance for some reason, a feedback signal is transmitted from the phototransistor 10' to the motor to prevent the subsequent supply of wafers. Each of the above methods can be selected as appropriate depending on the purpose.

The wafer sent onto the air chute is placed on an alignment table as shown in FIG. 4 at the other end of the air chute. First, the wafer 1 transferred to the other end of the air chute 8 is transferred onto the alignment table 12, and is sucked into a vacuum suction hole provided on the surface of the wafer 1, and a brake is applied to suppress the transfer speed. Then, the two guides 13 change the direction in a fixed direction. two guides 13
Three positioning pins 14 are provided at the center position between them as shown in C. Of these, the two pins at both ends remain fixed, but the one pin in the center is movable back and forth. It's getting old. Note that since an air blowing hole is also provided on the table 12 in addition to the vacuum suction hole, the wafer is in a floating state. In this state, as shown in E, the table 12 is tilted by the air cylinder 15 and rotated with the wafer 1 floating thereon to rotate the wafer. Then, when the wafer 1 is gradually rotated in the direction of the arrow as shown in C, it automatically stops as shown in D with the flat reference surface 16 of the periphery of the wafer 1 in contact with all three of the positioning pins 14. Positioning is performed. The table 12, which was tilted at this point, is returned to its original position.

The wafer, which has been positioned in a fixed direction as described above, is then spatially transferred onto a dicing table by a wafer chuck while maintaining this alignment direction. FIG. 5 shows a Perneut hat used as a wafer hat.

Wafer holding surface 1 whose size corresponds to the area of the wafer
Air supplied from a tube 19 on the back side of the holding surface 17 is blown from a plurality of nozzles 18 provided approximately in the center of the holding surface 17, and the air is blown onto a processing object such as a wafer to create a so-called Perneui process. It works to suck the wafer 1 according to the principle. Reference numeral 20 denotes a wafer positioning portion provided on a part of the peripheral edge of the holding surface 17, and the wafer is attracted to the holding surface 17 with this portion as a reference. However, this positioning part is not always necessary.

The wafer transferred onto the dicing table 21 (Fig. 2) is attracted by a vacuum chuck placed on the edge of this table, and by retracting the table itself, the wafer is transported directly below the microscope 22 for dicing. Positioning (alignment) is performed. This positioning work is carried out using the X, Y and θ
This is done by controlling a direction fine adjustment mechanism (not shown) to align the center of the dicing area of the wafer with a reference plane (aligned with the position of the dicing blade) provided on the microscope. A specific example of the positioning work will be described below with reference to FIG. A shows the relationship between the reference line 22 that first appears on the microscope and the dicing area 23, which naturally do not match. Therefore, next, as shown in B, first adjust the θ direction mechanism to complete the positioning in the θ direction, then adjust the Y direction mechanism as shown in C to complete the positioning in the Y direction, and finally in the same manner as D. The positioning work is completed by adjusting the X-direction mechanism to completely align the reference line 22 with the center of the dicing area 23.

Next, the dicing blade is scanned along the reference line 22 to first perform dicing in the dicing area in the Y direction (or X direction), and then the dicing table is rotated 90 times to perform dicing in the dicing area in the Perform dicing. The rotation of the dicing table can be performed automatically. Further, even if the centers of rotation of the wafer and the dicing table do not coincide, there is no problem when rotating the wafer by 90 degrees.

In addition, since conventional dicing equipment was equipped with a positioning mechanism only in two directions, θ and Y directions, when actually dicing, dicing was performed once in the Y direction at C in Fig. 6. After that, the dicing table had to be rotated 90 degrees and positioned in the X direction again as shown in D, and then dicing in the X direction had to be performed again. For this reason, continuous dicing in the X and Y directions is impossible, and the work must be interrupted midway and positioning must be done again, which inevitably leads to inefficiency in the work.

The width of the reference line 22 in the microscope is determined in consideration of the width of the dicing blade and the degree of chipping during the dicing operation. For example, if the width of the dicing blade is selected to be 30μ, the width including chipping will be approximately 50μ. Therefore, if this dimension is displayed on the reference line, there is no need to measure it each time with another measuring mechanism, and it can be known at a glance.

After the dicing operation has been completed, the wafer is returned to its original position by moving the dicing table using the dicing table moving mechanism. Then, the vacuum suction is released, and air is blown up to float above the table, where it is sucked by the perneutral chuck waiting above and sent to the next cleaning process.

By the way, when dicing the above-mentioned wafers, the wafers are cooled with liquid such as water, so it is very difficult to remove the wafers from the dicing table that are in close contact with the table due to water, etc., and many cracks occur. It was causing defects. For this reason, we considered the following method. FIG. 7 shows an air blowing method, in which A shows a top view and B shows a cross-sectional view, in which air 25 is partially blown onto the wafer 1 from the tube 24 from diagonally above the wafer 1 to blow the liquid around the wafer. It is something that we try to eliminate.

The wafers sucked from the dicing table by the Perny chuck are sent to the next cleaning step, which is carried out on another table separate from the dicing table, by rotating the chuck arm through 90 degrees.

8A and 8B show a method of cleaning the wafer transferred by the chuck, in which the wafer 1 is rotated while being held by the vacuum chuck 26 of the other table and water is sprayed from the nozzle 27 from above and below. Cleaning or spin cleaning is performed. After finishing, drain the water and spin dry as shown in B.
This cleaning step removes the deposits on the wafer and keeps it clean.

Next, the wafer is again sucked by the chuck and transferred to the wafer unloader by rotating the chuck arm 90 degrees. That is, the wafer is fed onto the air chute and is transferred in the opposite direction to the loader. An empty cartridge is set at the end of the air chute, and wafers are sequentially supplied to this cartridge.

The cartridge automatically rises one pitch at a time in accordance with the timing of supplying wafers, and these operating mechanisms can be operated in the opposite direction to that of the loader. When the cartridge is full, an alarm is automatically issued and the operator sets an empty cartridge. However, the setting and resetting of these cartridges can be performed automatically.

The wafers stored in the cartridges are sent to the next breaking step, where desired operations are performed and the wafers are separated into individual pellets.

As is clear from the above explanation, according to the above-mentioned dicing apparatus, the handling of wafers to be diced from the state in which they are loaded to the state in which they are diced and unloaded is all performed automatically, and no manual work is required. Therefore, the dicing work itself can be performed more intensively without having to spend time on extra preparatory work as in the past, and the number of work starts has increased significantly.

Furthermore, since manual handling is not required, mechanical damage to the wafers caused by this can be completely prevented.

Furthermore, by configuring the wafer loader and unloader devices adjacent to each other, the size of the device itself can be designed to be extremely compact. Since it is provided in the upper space of the chuck device for spatially transferring wafers between each work process, it does not take up any extra space. As shown in Figure 9, this chuck always rotates in a fixed direction intermittently so that wafers processed in each process are transferred to the next process at the same time, so there is no waste in movement and it is extremely efficient. work purposefully.

Although various modifications of each mechanism are shown in the text, the combinations thereof can be changed in various ways depending on the purpose, and the device of the present invention is not limited to specific combinations due to these changes. do not have.

[Brief explanation of the drawing]

1A to 1E are process diagrams showing the case of performing dicing work using a conventional device, FIG. 2 is a top view showing an overview of the device of the present invention, and FIGS. 3A to 3D are sectional views showing a wafer loader mechanism, FIG. 4 shows the wafer alignment mechanism, A, C, and D are top views, B and E are cross-sectional views, and FIG. 5 is a chuck mechanism, and A is a cross-sectional view.
B is a bottom view, FIGS. 6A to D are sectional views showing the method of positioning a wafer on a dicing table, FIG. 7 is a wafer air blow mechanism, A is a top view, B is a sectional view, and FIG. 8A 9 is a sectional view showing the wafer cleaning mechanism, and FIG. 9 is a trajectory showing the operating state of the wafer chuck. 1... Wafer, 2... Case, 3... Tweezers, 4, 21... Dicing table, 5... Dicing table, 6... Cartridge, 7...
Wafer loader position, 8...Air shoot, 9...
Light source, 10... Phototransistor, 11... Motor, 12... Positioning table, 13... Guide, 14... Positioning pin, 15... Air cylinder, 16... Wafer reference surface, 17... Chuck holding surface, 18, 27...nozzle, 19, 24
... tube, 20 ... stopper, 22 ... microscope reference line, 23 ... wafer dicing area, 25
...Air, 26...Vacuum chuck.

Claims (1)

[Claims] 1. A loader device for supplying wafers to a dicing device, an unloader device provided adjacent to this rotor device for storing wafers after dicing, and a loader device for transporting wafers unloaded from the loader device onto a dicing table. 1 conveying device,
A wafer positioning device that positions the wafer transferred onto the dicing table, a dicing device that dices the positioned wafer with a rotating blade, and a dicing table on which the wafer transferred by the first transfer device is placed. a dicing table moving mechanism for moving the wafer to the wafer positioning device and the dicing device and returning the dicing table from the dicing device to the location where the wafer was transferred by the first transfer device; a second transfer device that transfers the wafer to another table separate from the dicing table; a cleaning device that spin-cleans the wafer transferred to the other table; and a cleaning device that transfers the wafer on the other table to the unloader device. The dicing device includes a third transport device for transporting the wafer to the wafer loading device, and the dicing device is located at a location away from the transport path of each of the first to third transport devices and far from the loader device and the unloader device. An automatic dicing device characterized by the following: