TW202407781A - Chip transportation method that is used to transport a plurality of chips in a processing apparatus that includes a holding worktable for holding the plurality of chips thereon and a transport-out unit for removing the chips from the holding worktable - Google Patents

Abstract

The objective is to suck up and hold and transport all chips. The solution is a chip transportation method that is used to transport a plurality of chips in a processing apparatus. The processing apparatus comprises: a holding worktable that holds a packaged substrate that has been cut into the plurality of chips; and a transport-out unit that transports the plurality of chips out of the holding worktable. The chip transportation method includes the following steps: a sucking and holding step, in which a contact surface of a transportation unit presses on and attaches to the plurality of chips that are held on the holding worktable in order to suck up and hold the plurality of chips; and an elevating step, in which the contact surface is elevated after the sucking and holding step. A controller of the processing apparatus is controlled so that the sucking and holding step and the elevating step are each implemented twice or more.

Description

How to transport wafers

The present invention relates to a wafer transporting method that attracts, holds and transports a plurality of wafers.

For example, in the manufacturing process of semiconductor devices, the following method has been carried out: packaging substrates containing devices such as ICs and LSIs are respectively formed in a plurality of areas divided into a grid shape by a plurality of mutually orthogonal dividing lines. The chip is cut along a planned division line with a cutting device, thereby being divided into a plurality of packaged wafers (see, for example, Patent Document 1).

A cutting device that cuts a package substrate along a planned division line is provided with a holding table that holds the package substrate, and a transfer unit that carries out a plurality of wafers from the holding table. Here, the transfer unit is provided with a transfer pad, and the transfer pad has a contact surface on which a plurality of suction holes are formed, and the plurality of suction holes correspond to the plurality of wafers held on the holding table, and the plurality of wafers are held on the holding table. This transfer pad attracts and holds the device and carries it from the holding table to another place. Prior technical literature patent documents

Patent Document 1: Japanese Patent Application Publication No. 2013-065603

The problem to be solved by the invention

However, there is the following problem: when a plurality of wafers are suctioned and held by the transfer pad, if the wafer becomes smaller, all the wafers cannot be suctioned and held by only making the transfer pad contact the wafer once.

Accordingly, an object of the present invention is to provide a wafer transfer method that can attract, hold, and transfer all wafers. means to solve problems

According to the present invention, a wafer transportation method can be provided, which is to transport a plurality of wafers in a processing device. The processing device is provided with: a holding table that holds the packaging substrate divided into the plurality of wafers; and a transportation unit that moves the wafers from the holding table. The workbench moves out the plurality of wafers; and a controller controls the transport unit, The transfer unit has: a contact surface that contacts the plurality of wafers; a plurality of suction holes formed on the contact surface in a manner corresponding to the plurality of wafers; a suction path that connects the plurality of suction holes and the suction source; and a lift. unit to raise and lower the contact surface, The wafer transportation method includes the following steps: In the suction and holding step, the contact surface is pressed toward the plurality of wafers held on the holding workbench to attract and hold the plurality of wafers; and a rising step to raise the contact surface after the attracting and holding step, The controller controls the suction and holding step and the rising step to be performed two or more times each. Invention effect

According to the present invention, the suction and holding step of pressing the contact surface of the transfer unit toward the plurality of wafers held on the holding table to attract and hold the wafers, and the rising step of raising the contact surface after the suction and holding step are performed. By performing this process twice or more, the effect of increasing the probability of attracting, holding and transporting all the wafers by the transport unit can be obtained.

Form used to implement the invention

Hereinafter, embodiments of the present invention will be described based on the attached drawings.

First, based on FIGS. 1 to 4 , the basic structure of a cutting device for implementing the wafer transport method of the present invention will be described below. In addition, in the following description, the arrow directions shown in FIG. 1 are respectively referred to as the X-axis direction (left-right direction), the Y-axis direction (front-back direction), and the Z-axis direction (up-down direction).

The cutting device 1 shown in FIG. 1 is a device for cutting a rectangular plate-shaped package substrate W, and has the following main components: a holding table 10 to hold the package substrate W; and an unloading unit 20 to hold the package substrate W. The package substrate W placed in the cassette 2 is moved out to the temporary assembly 3; the first transport unit 30 transports the package substrate W temporarily placed in the temporary assembly 3 to the holding table 10; the cutting unit 40 is used to move along the The planned dividing line cuts the package substrate W held on the holding table 10; the upper surface cleaning component 50 cleans the upper surface of the packaging substrate W that has been cut by the cutting unit 40; the lower surface cleaning component 60 cleans the package substrate W that has been cut by the cutting unit 40. The lower surface of the package substrate W is cleaned; the lower surface drying assembly 70 dries the lower surface of the package substrate W that has been cleaned by the lower surface cleaning assembly 60; the second transport unit 80 holds the package substrate W on the holding table The package substrate W after cutting in 10 is transported to the lower surface drying assembly 70 through the lower surface cleaning assembly 60; A plurality of wafers C (see FIG. 4 ) fall into the wafer accommodating component 4; and the controller 100.

Next, the main components constituting the cutting device 1 , namely, the holding table 10 , the unloading unit 20 , the first transport unit 30 , the cutting unit 40 , the upper surface cleaning unit 50 , the lower surface cleaning unit 60 , and the lower surface drying unit are described below. The structures of the assembly 70, the second transport unit 80, the drop-in assembly 90 and the controller 100 will be described in sequence.

Here, the package substrate W is a CSP substrate in which devices such as ICs and LSIs are respectively formed in a plurality of areas set in a grid shape by a plurality of mutually orthogonal dividing lines, and the package substrate W is cut along the edges of the package substrate W by the cutting device 1 The chip is cut along the planned division line, thereby being divided into a plurality of packaged wafers C (see FIG. 4).

As shown in FIG. 1 , the holding table 10 is a rectangular plate-shaped member disposed almost in the center of the base 1A. The holding surface 11 (refer to FIG. 4 ) on the upper surface of the holding table 10 has openings corresponding to the packaging substrate W in a grid pattern. The plurality of areas in the shape correspond to round hole-shaped suction holes (not shown). Furthermore, as shown in FIG. 4 , these suction holes are connected to one suction path 13 through a plurality of suction paths 12 formed on the holding table 10 , and a pipe 14 is connected to the suction path 13 . Here, the pipe 14 is divided into two branch pipes 14a and 14b. One branch pipe 14a is connected to a suction source 15 such as a vacuum pump through an electromagnetic switching valve V1, and the other branch pipe 14b is connected to a suction source 15 such as a vacuum pump through an electromagnetic switching valve V2. It is connected to an air supply source 16 such as an air compressor. Furthermore, the electromagnetic switching valves V1 and V2 are electrically connected to the controller 100, and their switching actions are controlled by the controller 100 respectively.

Furthermore, as shown in FIG. 1 , the holding table 10 is supported by a disc-shaped support member 17 . The support member 17 and the holding table 10 can be rotated around a vertical central axis by a rotational drive mechanism (not shown). Rotate a predetermined angle (90°).

Then, the holding table 10 and the supporting member 17 can be moved along the X-axis direction (processing feed direction) by an X-axis direction moving unit (not shown), and can be positioned at the processing position where the package substrate W is cut. Move back and forth between the transfer position and the transfer position of the package substrate W. Furthermore, the X-axis direction moving component is composed of a conventional ball screw mechanism or the like.

As shown in FIG. 1 , the unloading unit 20 performs the following functions: taking out a package substrate W from the cassette 2 arranged in the support 1B, and temporarily placing the packaging substrate W in the temporary assembly 3 . The support 1B is configured The +Y-axis direction end (rear end) on the base 1A stands upright from the -X-axis direction end (left end) of the base 1A.

The first transport unit 30 is configured to transport the package substrate W temporarily placed in the temporary assembly 3 to the holding table 10, and is provided with a suction pad 31 that attracts and holds the upper surface of the package substrate W, supports the suction pad 31, and holds the package substrate W. The cylinder mechanism 32 that moves up and down, the actuator arm 33 that supports the cylinder mechanism 32, and the moving assembly (not shown) that moves the actuator arm 33 in the Y-axis direction (front and back direction). Furthermore, the cylinder mechanism 32 can also be replaced by a ball screw mechanism having a motor, a ball screw and a guide to move the suction pad 31 up and down.

Furthermore, an imaging unit 34 for detecting the area to be processed of the package substrate W is mounted on the cylinder mechanism 32 . The photographing component 34 is composed of an optical component such as a microscope or a CCD camera, and sends the captured image data toward the controller 100 .

The cutting unit 40 is a unit that cuts the package substrate W held on the holding table 10 along the planned division line, and is provided with a spindle housing 41 arranged along the indexing feed direction (Y-axis direction), and is rotatably provided. A spindle (not shown) is supported on the spindle housing 41 , a cutting insert 42 is installed at the front end of the spindle, and cutting water supply nozzles (not shown) are arranged on both sides of the cutting insert 42 .

The above-mentioned spindle housing 41 is movable in the Y-axis direction (indexing feed direction) by a Y-axis direction moving component (not shown), and the spindle and cutting insert 42 (not shown) are moved by a servo motor or the like. The rotation drive source (not shown) is rotationally driven at a predetermined speed. Furthermore, in this embodiment, the cutting insert 42 is an electroformed insert in which diamond abrasive grains are fixed to a disc-shaped insert base made of aluminum through nickel plating. In addition, during the cutting process of the package substrate W, cutting water is supplied to the cutting blade 42 and the cutting portion of the package substrate W from a cutting water supply nozzle (not shown).

As shown in FIG. 1 , it is disposed between the cutting unit 40 and the holding table 10 in the X-axis direction (machining feed direction), that is, above the movement path along the X-axis direction of the holding table 10 There is an upper surface cleaning unit 50 . The upper surface cleaning unit 50 cleans the upper surface of the package substrate W that has been divided into individual wafers C by the cutting process performed by the cutting unit 40 . The upper surface cleaning component 50 is a component that sprays cleaning water toward the upper surface of the package substrate W after cutting and is held on the holding table 10 to clean the upper surface of the package substrate W.

The lower surface cleaning unit 60 is a unit for cleaning the lower surface of the package substrate W that has been divided into individual wafers C by the cutting process of the cutting unit 40. As shown in FIG. 1, it is disposed in Keep the -Y-axis side (front side) of the table. The lower surface cleaning assembly 60 is provided with a pair of rotatable cleaning rollers 61 and a cleaning water supply unit (not shown) that supplies cleaning water to these cleaning rollers 61. Each cleaning roller 61 is driven by a sponge. Wait to form.

The lower surface drying component 70 is a component that dries the lower surface of the package substrate W whose lower surface has been cleaned by the lower surface cleaning component 60, and as shown in FIG. 1, is adjacent to the lower surface cleaning component in the Y-axis direction. The net assembly 60 is configured. The lower surface drying unit 70 includes a rectangular plate-shaped drying table 71 that attracts and holds the package substrate W whose lower surface has been cleaned by the lower surface cleaning unit 60, and a heater (not shown) as a heating unit.

The second transfer unit 80 is a unit for performing the transfer method of the wafer C of the present invention together with the holding table 10 , and has the following configuration: one of the package substrates W that has been cut and held on the holding table 10 A plurality of wafers C are sucked and held, and these wafers C are transported to the lower surface drying module 70 via the lower surface cleaning module 60 .

Here, the second transfer unit 80 is composed of a transfer pad 81 , an actuator arm 82 , a moving unit (not shown), and a lifting unit 5 . The transfer pad 81 is a package that has been cut and held on the holding table 10 . The upper surface of the plurality of divided wafers C of the substrate W is sucked and held. The actuating arm 82 supports the transfer pad 81, and the moving assembly moves the actuating arm 82 and the transfer pad 81 together in the Y-axis direction ( The lifting unit 5 moves the conveying pad 81 and the actuating arm 82 up and down in the Z-axis direction (up-and-down direction).

The conveying pad 81 is a rectangular plate-shaped member and is horizontally attached to the lower end of the actuating arm 82 . Furthermore, as shown in FIGS. 2 to 4 , a rectangular contact surface 83 is installed on the lower surface of the transfer pad 81 , and as shown in FIG. 2 , the contact surface 83 has a plurality of openings in a matrix shape. (4 columns × 7 rows = 28 in the illustrated example) round hole-shaped suction holes 83a. Furthermore, the number of suction holes 83a can be arbitrarily set according to the number of wafers C to be divided and manufactured.

As shown in FIG. 4 , a plurality of suction holes 83 a opened in the contact surface 83 are connected to a suction path 85 through a plurality of suction paths 84 formed in the contact surface 83 , and a pipe 86 is connected to the suction path 85 . Furthermore, the pipe 86 is connected to a suction source 87 such as a vacuum pump through the electromagnetic switching valve V3. Furthermore, the electromagnetic switching valve V3 is electrically connected to the controller 100, and its switching action is controlled by the controller 100.

In addition, as shown in FIG. 3 , the lifting unit 5 is configured by a ball screw mechanism accommodated in the support column 1B (see FIG. 1 ). This ball screw mechanism is provided with a vertical ball screw shaft 6 threaded through an actuator arm 82, a servo motor 7 as a rotational driving source connected to the upper end of the ball screw shaft 6, and a guide actuator arm 82 and a receiving end thereof. The guide rail 8 supports the lifting and lowering of the conveying pad 81.

Therefore, when the servo motor 7 is started to cause the ball screw shaft 6 to rotate forward and reverse, the actuating arm 82 screwed to the ball screw shaft 6 will move up and down along the guide rail 8, so the conveying pad 81 supported by the actuating arm 82 will Lifts and lowers together with the actuating arm 82.

As shown in FIG. 1 , the drop assembly 90 is used to dry the upper surface of the plurality of wafers C of the package substrate W held on the drying table 71 of the lower surface drying assembly 70 , and to dry the wafers C. It is configured to fall into the input port 4a of the wafer accommodating unit 4 arranged adjacent to the lower surface drying unit 70. This drop-in assembly 90 includes a warm air jet nozzle 91 that jets warm air toward the upper surface of the wafer C, a drop brush 92 installed on the warm air jet nozzle 91, and a cylinder mechanism 93 that raises and lowers the warm air jet nozzle 91. , an actuator arm 94 that supports the cylinder mechanism 93, and a moving assembly (not shown) that moves the actuator arm 94 in the Y-axis direction. Furthermore, a drawer 95 for allowing the wafer storage container (not shown) of the wafer storage assembly 4 to enter and exit is provided on the front wall (+X-axis direction end surface) of the base 1A.

The controller 100 has a CPU (Central Processing Unit) that performs calculation processing according to a control program, and a ROM (Read Only Memory) or RAM (Random Access Memory), etc. memory, etc. The controller 100 receives the photographic data from the photographing unit 34 and controls the rotation drive mechanism (not shown) of the holding table 10, the unloading unit 20, the first conveying unit 30, the cutting unit 40, the upper surface cleaning unit 50, The lower surface washing unit 60, the lower surface drying unit 70, the second transport unit 80, the drop unit 90, and the like.

Next, the operation of the cutting device 1 constructed as above will be explained.

During the cutting process of the package substrate W by the cutting device 1 , the package substrate W accommodated in the cassette 2 can be taken out by the unloading unit 20 and temporarily placed in the temporary assembly 3 . In this temporary assembly 3, the package substrate W will be aligned, and the aligned package substrate W can be held by the first transport unit 30 and transported to the holding workbench 10, and then be attracted and held on the holding workbench. 10 on.

On the other hand, in the processing position, when an image is obtained by photographing the front surface of the package substrate W by the imaging unit 34, the pattern matching process based on the image can be used to detect the stress. Predetermined dividing line for cutting. When the planned dividing line of the package substrate W is detected in this way, the position of the cutting blade 42 of the cutting unit 40 in the Y-axis direction (indexing movement direction) can be indexed and moved by indexing (not shown). For the assembly, the position of the cutting blade 42 in the Y-axis direction is aligned with the position of the planned dividing line of the package substrate W to be cut.

Then, from the above state, the cutting insert 42 is lowered by a predetermined cutting amount by a lifting mechanism (not shown) while being rotated at a high speed, and the X-axis moving assembly (not shown) is used to move the holding table 10 and the The package substrate W held on the holding table 10 moves in the -X-axis direction. In addition, cutting water is supplied to the cutting water nozzle from a water supply source (not shown), and the cutting water is sprayed toward the cutting insert 42 from the cutting water nozzle.

In this way, in the processing position, the package substrate W held on the holding table 10 is cut by the cutting blade 42 along the planned division line while receiving the supply of cutting water. Moreover, after the above-mentioned cutting process of the package substrate W is performed along all the planned division lines in one direction, the holding table 10 and the parts already held on the holding table 10 can be separated by a rotational drive mechanism (not shown). The package substrate W is rotated 90°, and the cutting process is similarly performed along the planned dividing line in another direction orthogonal to the planned dividing line that has been cut. Then, after cutting along all the planned division lines of the package substrate W is completed, the package substrate W can be divided into a plurality of wafers C on which devices are mounted one by one.

When the cutting process of the package substrate W by the above cutting unit 40 is completed, the package substrate W will be attracted and held by the second transport unit 80 and pass from the holding table 10 through the upper surface cleaning assembly 50 and the lower surface cleaning assembly. 60 to the lower surface drying assembly 70. During the transportation process of the packaging substrate W, the upper surface and lower surface of the packaging substrate W will be cleaned by the upper surface cleaning assembly 50 and the lower surface cleaning assembly 60 respectively. Moreover, the packaging substrate W whose upper and lower surfaces have been cleaned will be attracted and held on the drying workbench 71 of the lower surface drying assembly 70, and the lower surface is dried by the lower surface drying assembly 70, and by falling from the The warm air injected from the warm air injection nozzle 91 of the assembly 90 is used to dry the upper surface. Then, the plurality of divided wafers C of the package substrate W whose upper and lower surfaces have been dried are dropped into the assembly 90 and put into the inlet 4 a of the wafer accommodating assembly 4 .

In this way, in the chip accommodating assembly 4, the plurality of inserted wafers C are accommodated in the chip accommodating container (not shown), and the series of cutting processing of one package substrate W is completed. When the cutting process of the plurality of package substrates W is continuously performed in this way and a predetermined amount of wafers C are placed in the chip accommodating container, the drawer 95 can be pulled out to take out the chip accommodating container, and the wafer C can be recovered. Finally, the empty wafer accommodating container is set to the wafer accommodating assembly 4 .

Next, an embodiment of the method of transporting the wafer C according to the present invention will be described.

Hereinafter, in the cutting device 1 , the plurality of divided wafers C that have been sucked and held on the holding table 10 of the package substrate W are sucked and held by the second transfer unit 80 and transferred to the lower surface drying unit 70 Implementation form will be explained.

The wafer C transfer method of the first embodiment is characterized by performing the 1) suction and holding step and the 2) lifting step described below two or more times (three times in this embodiment).

In the suction and hold step, the controller 100 sets the number n of the suction and hold step and the rising step to 0 (n=0) as an initial setting (step S1 in FIG. 6 ). Next, the controller 100 opens one of the electromagnetic switch valves V2 shown in FIG. 4 and closes the other electromagnetic switch valve V1 (step S2). In this way, the air from the air supply source 16 is ejected from the branch pipe 14 b through the pipe 14 and the suction passages 13 and 12 from a plurality of suction holes (not shown) opened in the holding surface 11 of the holding table 10 . Therefore, the plurality of divided wafers C of the package substrate W held on the holding surface 11 of the holding table 10 can be easily separated from the holding surface 11 .

In the above state, the transfer pad 81 of the second transfer unit 80 is positioned above the package substrate W as shown in FIG. 5(a) (step S3 in FIG. 6), and is moved by the lifting unit 5 shown in FIG. 3 The transfer pad 81 is lowered, and as shown in FIG. 5( b ), the plurality of wafers C on the holding table 10 are pushed by the contact surface 83 of the transfer pad 81 , and the wafers C are attracted and held on the contact surface 83 (Step S4: Attraction and holding step). Furthermore, at this time, because the controller 100 has opened the electromagnetic switch valve V3 shown in FIG. 4 , the negative pressure from the suction source 87 will pass through the pipe 86 and the suction paths 85 and 84 and reach the suction hole 83a of the contact surface 83 (Refer to Figure 2). Therefore, although the plurality of wafers C on the holding table 10 can be attracted and held by the negative pressure on the contact surface 83 of the transfer pad 81, there may be cases where not all the wafers C are attracted and held on the contact surface 83. , and a part of the wafer C remains on the holding surface 11 of the holding table 10 .

In the next rising step, the conveying pad 81 is raised by a predetermined height h as shown in FIG. 5(c) by the lifting unit 5 shown in FIG. 3 (step S5: rising step). Here, the predetermined height h at which the transfer pad 81 rises is set smaller than the thickness t of the wafer C (h<t). In this way, by setting the predetermined height h of the transfer pad 81 to be smaller than the thickness t of the wafer C, the wafer C that has been attracted and held on the contact surface 83 of the transfer pad 81 and the wafer C that has not been attracted and held will be in the height direction. Since Δh shown in FIG. 5(c) overlaps in the height direction, the wafer C that is not attracted by the contact surface 83 of the transfer pad 81 can be held on the bottom surface of the holding surface 11 of the holding table 10, relative to the holding The angle of inclination of the surface 11 is limited to less than 90°, preferably less than 30°, so that there is no possibility of standing up between the contact surface 83 and the holding surface 11 .

Next, count the number n (n=n+1) of the suction and holding step (step S4) and the rising step (step S5) (step S6), and determine whether the counted number n has reached the preset number (in this implementation 3 times in the form) (step S7). When the number n of the suction and hold step (step S4) and the rising step (step S5) has not reached the predetermined number of times (n=3) (step S7: No), the suction and hold step (step S4) and the rising step are repeated. (Step S5) and the count of the number of times n (n=n+1). When the number of times n has reached the preset number of times (3 times) (Step S7: Yes), the lifting unit 5 shown in Figure 3 is driven. As shown in FIG. 5(d) , the transfer pad 81 is raised to a height greater than the thickness t of the wafer C (step S8).

Here, in this embodiment, the number n of repeating the suction and holding step (step S4) and the rising step (step S5) is set to three times (n=3). However, it is empirically known that the following situation occurs: as long as By repeating the suction and holding step and the lifting step three times, as shown in FIG. 5(d) , all the wafers C can be suctioned and held on the contact surface 83 of the transfer pad 81 . However, this number n is not a number that is uniformly set according to the size or number of wafers C. It only needs to be two or more times. It can be set to an appropriate number of times according to the size or number of wafers C.

As a result of repeating the above suction and holding step and the lifting step for a predetermined number of times (three times), as shown in FIG. 5(d) , the transfer pad 81 holding all the wafers C on the contact surface 83 will be transferred to The lower surface drying module 70 is shown in FIG. 1 (step S9), and the series of transportation of the wafer C by the transportation method of this embodiment is completed (step S10).

As described above, in this embodiment, since the suction and holding step and the lifting step are performed three times, it is possible to obtain the effect that all the wafers C can be suctioned, held and transported by the transfer pad 81 . The suction and holding step is performed three times. The contact surface 83 of the transfer pad 81 is pressed against the plurality of wafers C held on the holding surface 11 of the holding table 10 to attract and hold the wafers C. The aforementioned rising step is to make the transfer pad 81 move after the suction and holding step. Steps to Ascent.

Next, a second embodiment of the wafer C transportation method of the present invention will be described based on FIGS. 7 and 8 . In addition, in FIG. 7 , the same elements as those shown in FIG. 4 are assigned the same reference numerals, and further description thereof will be omitted below.

In this embodiment, as shown in FIG. 7 , a pressure gauge 88 is installed in the middle of the pipe 86 , and the controller 100 is set so that the absolute value |P| of the negative pressure P detected by the pressure gauge 88 is lower than When the predetermined threshold |P ₀ | is reached (|P|<|P ₀ |), the attraction and holding step and the rising step described in the first embodiment are executed again. That is, when the absolute value |P| of the negative pressure P is lower than the predetermined threshold value |P ₀ | (|P _| The contact surface 83 attracts the wafer C, thereby causing air leakage. Therefore, in this embodiment, if the absolute value |P| of the negative pressure P is greater than the predetermined threshold value |P ₀ |, it is determined that all the wafers C have been sucked and held on the transfer pad 81 . However, in this embodiment, it is assumed that even if the suction holding step and the rising step are repeated a preset number of times (5 times in this embodiment), the absolute value |P| of the negative pressure P is still lower than the predetermined value. When the threshold value |P ₀ | is (|P|<|P ₀ |), it is determined that the transfer pad 81 cannot attract and hold all the wafers C for some reason, and an error is reported and the process is interrupted.

Hereinafter, the method of transferring the wafer C according to this embodiment will be described based on the flowchart shown in FIG. 8 .

In the method of transferring the wafer C in this embodiment, similarly to the first embodiment, the controller 100 sets the number n of the suction and holding steps and the rising steps to 0 (n=0) as the initial setting (step S11). . Next, the controller 100 opens one of the electromagnetic switch valves V2 shown in FIG. 7 and closes the other electromagnetic switch valve V1 (step S12). In this way, the air from the air supply source 16 is ejected from the branch pipe 14 b through the pipe 14 and the suction passages 13 and 12 from a plurality of suction holes (not shown) opened in the holding surface 11 of the holding table 10 . Therefore, the plurality of divided wafers C of the package substrate W held on the holding surface 11 of the holding table 10 can be easily separated from the holding surface 11 .

In the above state, the transfer pad 81 of the second transfer unit 80 is positioned above the package substrate W as shown in Fig. 5(a) (step S13), and the transfer pad is moved by the lifting unit 5 shown in Fig. 3 81 descends, and as shown in FIG. 5(b) , the contact surface 83 of the transfer pad 81 pushes the plurality of wafers C on the holding table 10 to attract and hold the wafers C to the contact surface 83 of the transfer pad 81 (Step S14: Attraction and holding step).

Next, the rising step (step S15) is executed in the same manner as in the first embodiment. That is, in the raising step, the conveying pad 81 is raised to a predetermined height h as shown in FIG. 5(c) by the lifting unit 5 shown in FIG. 3 .

When the above-mentioned rising step (step S15) is executed, the negative pressure P of the pipe 86 can be measured by the pressure gauge 88 shown in FIG. 7 (step S16). Then, the number n (n=n+1) of the suction holding step (step S14) and the rising step (step S15) is counted (step S17), and the absolute value of the negative pressure P of the pipe 86 measured by the pressure gauge 88 is determined. Whether the value |P| has exceeded a predetermined threshold value |P ₀ | (step S18).

When the absolute value |P| of the negative pressure P in the pipe 86 measured by the pressure gauge 88 exceeds the predetermined threshold value |P ₀ | (|P|>|P ₀ |) (step S18: Yes), It is judged that all the wafers C are attracted and held by the contact surface 83 of the transfer pad 81, and the lifting unit 5 shown in FIG. 3 is driven to raise the transfer pad 81 by a thickness greater than the wafer C as shown in FIG. 5(d). t is a greater height (step S19). Then, the transfer pad 81 holding all the wafers C is sucked and held on the contact surface 83 and transferred to the lower surface drying assembly 70 shown in FIG. 1 (step S20). The transfer of the wafer C by the transfer method of this embodiment is End (step S21).

On the other hand, when the absolute value |P| of the negative pressure P in the pipe 86 measured by the pressure gauge 88 does not exceed the predetermined threshold value |P ₀ | (|P|<|P ₀ |) (step S18 : No), it will be determined whether the number n of suction holding steps and rising steps has reached 5 times (step S22). Here, if the number n of the suction and holding steps and the rising steps is less than 5 (step S22: No), the processing of steps S14 to S18 including the sucking and holding steps and the rising steps will be repeated.

Furthermore, when the number n of repetitions of the suction holding step and the rising step reaches 5 times (S22: Yes), that is, even if the suction holding step and the rising step are repeated 5 times, the pressure in the pipe 86 measured by the pressure gauge 88 When the absolute value |P| of the negative pressure P does not exceed the predetermined threshold |P ₀ | (|P|<|P ₀ |), an error is displayed (step S23) and the process ends (step S21). .

As described above, in this embodiment, it is assumed that the absolute value |P| of the negative pressure P detected by the pressure gauge 88 is lower than the predetermined threshold value |P ₀ | (|P|<|P ₀ |), the suction and holding step and the lifting step are performed again, so that all the wafers C can be sucked, held and transported by the transfer pad 81, and the effect can be obtained.

Furthermore, in this embodiment, the upper limit of the number of repetitions n of the suction and holding step and the ascending step is set to 5 times. However, the upper limit of the number of repetitions n can be set to any number as long as it is a plurality of times.

Furthermore, in this embodiment, although the upper limit of the number of times n is set to n=5 (5 times), the absolute value |P| of the negative pressure P of the pipe 86 measured by the pressure gauge 88 does not exceed The repetition of the suction and hold step and the rise step under the predetermined threshold value |P ₀ | (|P|<|P ₀ |) can also be set to measure the time when the suction hold step and the rise step are repeated, and The attraction and holding step and the rising step are repeated until the measured time reaches the upper limit.

By the way, the above description has been made on the mode in which the present invention is applied to the method of transporting the wafer C by the second transport unit 80 in the cutting device 1 for cutting the package substrate W. However, the present invention is not suitable for processing the package substrate. The same method can be applied to the wafer transportation method in any workpiece processing apparatus other than W.

Furthermore, in the above embodiment, in the suction and holding step, the pressure of the air blown out from the holding table 10 and the pressing force of the transfer pad 81 on the wafer C are fixed. However, these air pressures may also be set to be constant. The pushing force becomes higher as the number n of the suction holding step and the rising step increases.

In addition, the present invention is not limited to the above-described embodiments, and it goes without saying that various modifications can be made within the scope of the patent application and the technical ideas described in the specification and drawings.

1: Cutting device 1A: Base 1B: Pillar 2: Cassette 3: Temporary assembly 4: Wafer accommodating assembly 4a: Inlet 5: Lifting unit 6: Ball screw shaft 7: Servo motor 8: Guide rail 10: Keep working Station 11: Holding surface 12, 13, 84, 85: Suction path 14, 86: Piping 14a, 14b: Branch pipe 15, 87: Suction source 16: Air supply source 17: Support member 20: Unloading unit 30: First transport Unit 31: Suction pad 32: Cylinder mechanism 33, 82, 94: Actuating arm 34: Shooting assembly 40: Cutting unit 41: Spindle housing 42: Cutting blade 50: Upper surface cleaning assembly 60: Lower surface cleaning assembly 61: Washing roller 70: Lower surface drying unit 71: Drying table 80: Second transport unit 81: Transport pad 83: Contact surface 83a: Suction hole 88: Pressure gauge 90: Drop unit 91: Warm air injection nozzle 92: Drop Inserting brush 93: Cylinder mechanism 95: Drawer 100: Controller C: Wafer h: Lifting height of transfer pad Δh: Overlapping height of wafer P: Negative pressure P ₀ : Threshold of negative pressure t: Wafer thickness V1, V2, V3 :Solenoid switch valve W: Package substrate S1~S10, S11~S23: Step+X,-X:X-axis direction+Y,-Y:Y-axis direction+Z,-Z:Z-axis direction

FIG. 1 is a partial perspective view of a cutting device used to implement the wafer transport method of the present invention. Fig. 2 is a bottom view of the transfer pad. FIG. 3 is a side view of the lifting unit of the cutting device shown in FIG. 1 . 4 is a schematic structural diagram of a transfer unit for implementing the wafer transfer method according to the first embodiment of the present invention. 5 (a) to (d) are partial side views of the main parts of the transfer unit showing the procedure for implementing the wafer transfer method of the present invention in the order of steps. FIG. 6 is a flowchart showing a procedure for implementing the wafer transfer method according to the first embodiment of the present invention. 7 is a schematic structural diagram of a transfer unit for implementing the wafer transfer method according to the second embodiment of the present invention. FIG. 8 is a flowchart showing a procedure for implementing the wafer transfer method according to the second embodiment of the present invention.

5:Lifting unit

10: Keep the workbench

11: Keep the surface

12,13,84,85: Attraction Road

14,86:Piping

14a,14b: Branch pipe

15,87: source of attraction

16: Air supply source

81:Transfer pad

83:Contact surface

100:Controller

C:wafer

V1, V2, V3: electromagnetic switch valve

Claims (3)

A method of transporting wafers is to transport a plurality of wafers in a processing device. The processing device is equipped with: Maintain the workbench and maintain the packaging substrate that has been divided into the plurality of wafers; a transport unit to transport the plurality of wafers from the holding stage; and The controller controls the transport unit, The transfer unit has: The contact surface is in contact with the plurality of wafers; A plurality of suction holes are formed on the contact surface in a manner corresponding to the plurality of wafers; The suction path connects the plurality of suction holes and the suction source; and The lifting unit makes the contact surface rise and fall, The wafer transportation method includes the following steps: In the suction and holding step, the contact surface is pressed toward the plurality of wafers held on the holding workbench to attract and hold the plurality of wafers; and a rising step to raise the contact surface after the attracting and holding step, The controller controls the suction and holding step and the rising step to be performed two or more times respectively. As claimed in claim 1, the wafer transporting method, wherein the transport unit includes a pressure gauge for detecting the pressure of the suction path, The controller is controlled to execute the suction holding step and the rising step again when the absolute value of the negative pressure detected by the pressure gauge is lower than a predetermined threshold. The wafer transporting method of claim 1 or 2, wherein in the rising step, the contact surface is raised to a height smaller than the thickness of the wafer.

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