JP2648123B2 - Semiconductor wafer clamping device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor wafer clamping device, and more particularly to a vacuum tweezer for sucking and transferring semiconductor wafers one by one.

[0002]

2. Description of the Related Art In a mass production process of semiconductor wafers, a refilling machine for transferring a large number of semiconductor wafers arranged in a carrier to another carrier at a time is often used.

[0003] However, in a case where an arbitrary one of the wafers is taken out and examined, or in a trial production test line, vacuum tweezers capable of sucking semiconductor wafers one by one is a convenient clamping device.

Referring to Japanese Patent Application Laid-Open No. 61-102468, which shows this kind of vacuum tweezers for holding a semiconductor wafer, as shown in the sectional view of FIG. 5A and the plan view of FIG. U-shaped cross-section holding plates 35, 36 for holding the wafer 37, sealing members 38, 39 for sealing both side surfaces of the holding plates 35, 36, and the holding plates 35, 36 and the sealing member. And a pipe 42 for connecting the space formed by 38 and 39 to the exhaust means. A U-shape is formed by a force generated by exhausting the space with the wafer 37 sandwiched between the holding plates 35 and 36. A tweezers is shown in which one of the holding plates 35, 36 is made flexible so that the gap between the holding plates 35, 36 is reduced.

[0005]

However, in such a pair of tweezers, the air in the space 40 surrounded by the holding plates 35, 36 and the wafer 37 is drawn through the pipe 42, so that the wafer 37 The stresses 60 and 61 pressing both main surfaces of the first and second surfaces and the stress 53 trying to draw in the direction of the pipe 42 act. Due to the two stresses, not only is there a concern that abrasion may occur on both main surfaces of the wafer 37, but also the surface of the ware 37 is pressed against the sealing members 38 and 39.
There is a concern that the side surface of the sealing member 7 may be damaged.
There is a concern that air may flow in from the seal gap 50 between the holding plates 8 and 39 and the holding plates 35 and 36 and from the wafer gap 51 between the sealing members 38 and 39 and the side surfaces of the wafer 37, so that the holding wafer 37 drops. As a result, there was a risk of a breakage accident. If the side surface of the wafer 37 is damaged, the wafer may be separated and generate dust, which may cause a reduction in the reliability of the subsequent process. In addition, the sealing members 38 and 39 and the holding plates 35 and
36 are rubbed against each other when the wafer 37 is attached and detached, which may cause dust generation.

In addition, in this example, vacuum tweezers are shown as a conventional example in which a suction surface having a large number of suction ports is brought into contact with one main surface of a semiconductor wafer to suck the suction surface.
As the diameter of the semiconductor wafer increases from 6 inches to 8 inches or more, a strong suction force is required, and the area of the suction surface needs to be increased. For this reason, the suction surface directly contacts the circuit function area formed on one main surface of the semiconductor wafer, and there is a concern that the circuit function may be damaged. There is no problem if the main surface on the opposite side of the semiconductor wafer is sucked, but especially when using vacuum tweezers by hand, the main surface of the wafer may be inadvertently sucked, which essentially solves the problem It has not been.

In particular, when a semiconductor wafer is stored in or taken out of a carrier having grooves arranged at a narrow pitch, tweezers having a size exceeding the separation distance from a nearby semiconductor wafer cannot be used. For example, there is also a restriction that there must be no structure exceeding the above dimensions such as an exhaust pipe.

When a semiconductor wafer is sucked with tweezers, it is excellent to abut on the substantially central portion of the wafer in that there is little fear of dropping. Touch, there is a worry of damage.

In order to solve the above problems, the present invention has the following problems.

(1) To provide a strong suction force without damaging the circuit function area of the semiconductor wafer.

(2) To prevent abrasion on the main surface of the semiconductor wafer.

(3) To prevent the held semiconductor wafer from dropping due to reduced airtightness.

(4) To be able to stably hold a semiconductor wafer having a large size.

(5) To prevent damage to the semiconductor wafer due to careless mistakes in the operation of tweezers.

(6) The structure must not be pinched after the front and back sides of the semiconductor wafer are identified.

(7) Even when a large number of semiconductor wafers are arranged at a narrow pitch, a wafer at an arbitrary position can be easily taken out without damaging nearby wafers. Conversely, even on narrow pitches, without damaging
Provide easy storage.

(8) Avoid generation of dust during operation.

(9) Minimize the portions that rub against each other as much as possible.

(10) A highly reliable semiconductor device can be supplied without lowering the production yield of semiconductor wafers.

(11) The reliability should not be reduced in the subsequent manufacturing process.

[0021]

SUMMARY OF THE INVENTION A semiconductor wafer clamping device according to the present invention comprises a first suction portion for sucking one main surface of a semiconductor wafer and a second suction portion for sucking another main surface of the wafer.
And a support portion having a path through which intake air for adsorbing the air passes therethrough and elastically connected to the first and second suction portions at a predetermined distance from each other. I do.

In particular, the first and second suction portions are provided with an intake port and an intake path, respectively.

In particular, the support section has a movable section which moves by suction pressure in a direction away from the side face of the semiconductor wafer to which the semiconductor wafer is sucked, and more particularly, the movable section moves the first section by the suction pressure. It is characterized by having elastic resilience in a direction in which the first and second suction portions are brought closer to each other.

In particular, the support portion has a base portion having a dimension larger than the arrangement pitch of the semiconductor wafers.

[0025]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to FIG. 1 showing a central sectional view of a vacuum tweezer of one embodiment of the present invention, and FIG. 2 showing a right half of a plan view of the vacuum tweezer, a vacuum tweezer of this embodiment has a first tweezer. , The second suction unit 2,
It includes a suction part 8, a support part 21, a base part 4, and a grip part 7.

Here, the first suction part 1 has a first suction surface 14 in contact with one main surface of the semiconductor wafer inside, and nine suction ports 12 are opened in the suction surface 14. Inside, there is an intake path 11 which connects all of these intake ports 12, and this intake path 11 has an intake path 1 at a side end.
1 'and the intake path 13. First suction unit 1
A guide 10 on a taper is formed at the upper end of the semiconductor wafer to facilitate housing of the semiconductor wafer. The upper end of the first suction unit 1 is bent along the circular edge of the semiconductor wafer (FIG. 2).

Here, since the first suction unit 1 and the second suction unit 2 have a contrasting structure, the description of the second suction unit 2 is omitted.

The first and second suction portions 1 and 2 are integrally connected by a suction portion 8 while being separated from each other by a distance exceeding the thickness of the semiconductor wafer. This suction unit 8
A side surface movable portion 9 having a side surface 17 opposed to a side surface of the semiconductor wafer is provided. Inside the pair of intake passages 11 ′ connected to an intake passage 116, the pair of intake passages 11 ′ are connected and relatively large. A suction path 13 having an inner space. The suction unit 8 includes first and second suction units 1 and 2.
The elastic member has elasticity that can move along the suction directions 20 and 20 ′, and elasticity that allows the side movable portion 9 to move along the downward suction direction 16.

The support portion 21 includes first and second suction portions 1 and 2.
2. It has an exhaust path 3 supporting the suction section 8 and communicating with the suction path 13, and has a pipe shape. The base portion 4 elastically fixes the support portion 21 so as to be able to move slightly back and forth and left and right, and also has a role of a stopper. Therefore, there is no accident that would cause damage. The grip 7 fixes the base 4 and
It has a diameter that makes it easy to hold with one hand, and has a switch 5 for selecting whether to absorb the air in the exhaust path 3 to make it a state close to a vacuum state or to make the air pressure almost the same as the outside air. Although not shown, the lower end of the grip 7 is connected to a vacuum pump via an elastic pipe.

The first and second suction parts 1 and 2, the suction part 8, and the support part 21 are made of synthetic rubber having a low electric insulation.
It is preferable that the base portion 4, the grip portion 7, and the like be made of a synthetic resin having low electrical insulation, since the circuit function of the semiconductor wafer is not destroyed due to the generation of static electricity.

In FIG. 2, only the right side of the center line 19 is shown and the left side is omitted. However, since the center line 19 is symmetrical with respect to the axis of symmetry, the left side is not shown. FIG. 1 is a cross-sectional view taken along the center line of FIG. 2 and the cut surface is viewed from the left side.

Referring to FIG. 3 showing a state in which the semiconductor wafer is sucked by using the vacuum tweezers configured as described above, the semiconductor wafer 6 is quietly placed between the first and second suction portions 1 and 2. Is operated by holding the grip portion 7 in a hand so as to be inserted into the device.

Next, when the switch 5 is pressed at the time when the semiconductor wafer 6 is almost inserted, the suction from the air inlet 12 is started. One main surface of the semiconductor wafer 6 is the first suction surface 14.
Meanwhile, the opposite main surfaces are in close contact with the second suction surfaces 15, respectively. The surface of the contact portion is the wafer contact surface 18 shown by oblique lines in FIG. Here, when the insertion angle of the semiconductor wafer 6 is remarkably shifted, it is conceivable that one of the suction parts does not perform the suction operation. As a result, the two adsorbing portions 1 and 2 perform the adsorbing operation in sequence.

When there is no more air from the closely attached intake port 12, the side movable section 9 is immediately sucked downward, and
Leaves the side of the semiconductor wafer. In this space, the side surface 17 in FIG. 2 is open to the side end, so that the inflow and outflow of air are free.

As described above, the semiconductor wafer is only subjected to the stress of pressing from the direction perpendicular to both main surfaces, and there is no stress for drawing the side surface of the semiconductor wafer in the direction of the exhaust path 3. There is no fear of abrasion on the main surface, and therefore no risk of dust generation. Further, even if the first and second suction portions 1 and 2 touch the circuit configuration area on the main surface of the semiconductor wafer, there is no fear of circuit damage.

When the semiconductor wafer 6 is placed at a desired position, it must be released. At this time, by releasing the finger pressing the switch 5, the suction force disappears,
Next, gently retract the tweezers.

The distance between the first and second suction surfaces 14 and 15 is
The thickness must be larger than the thickness of the semiconductor wafer 6.
A margin of 2 mm or more and 0.6 mm or less is preferable. The thickness of the first and second suction portions 1 and 2 needs to be smaller than the pitch at which the semiconductor wafers 6 are arranged, and is preferably a dimension that allows a margin of 2.0 mm or more.

According to this embodiment, since the double-sided suction structure is used, a strong suction force can be obtained even if the suction surface is small. In other words, the transfer can be performed with confidence without dropping without touching the circuit forming area. Also, there is no need to pay attention to the front and back surfaces of the semiconductor wafer. Large size wafers can be handled with confidence.

Further, since no stress such that the main surfaces of the wafer rub against each other is applied, there is no need to worry about dust generation, and it is possible to eliminate the cause of lowering the reliability of the subsequent process.

According to this embodiment, nine intake ports 12 are arranged in a line, but the present invention is not limited to this.
It is also possible to change as appropriate such as arranging ten pieces in two rows. In this embodiment, the case of tweezers held by hand has been described. However, the present invention is not limited to this.
It may be used on a line where the suction control is automated. In this case, the structure of the grip part 7 is appropriately changed.

Referring to the sectional view of FIG. 4 showing a vacuum tweezer according to another embodiment of the present invention, this embodiment has an intake port and an intake path inside first and second suction portions 1 'and 2'. This embodiment is the same as the above-described embodiment except for the absence of the above-described structure and the structure of the suction unit 8 ', so that the description of the common parts will be omitted.

In this embodiment, the first and second suction portions 1 ', 1'
Numeral 2 'does not directly adsorb the main surface of the semiconductor wafer, but takes the form of clamping by the action of the suction directions 22, 22'. This suction action is transmitted indirectly by the action of the suction section 8 '. The suction section 8 'has an intake passage 1 inside.
1, a suction path 13 'is provided. The thickness between the suction passage 13 'and the outside is set to be larger than the thickness between the suction passage 11 and the outside. The side movable portion 9 ′ having the side surface 17 forms a relatively thick block, and moves elastically in the direction of the exhaust path 3 by the intake pressure.

Now, when the exhaust is started by the operation of the switch 5, the movable portion 9 'moves in the direction of the exhaust path 3 by the negative pressure, and the suction path 13' is narrowed. Moving. For this reason, a stress in a direction approaching each other is applied to the first suction portion 1 'and the second suction portion 2', and the semiconductor wafer 6 is clamped as in the case of FIG.

The clamping force of the semiconductor wafer 6 of this embodiment is
Because it is weaker than in the case of the above one embodiment,
It may be used for a semiconductor wafer having a relatively small size, or an exhaust motor having a stronger exhaust force may be used.

The structure of an unexplained part of this embodiment,
The effects and application examples are the same as or similar to those of the above-described embodiment, and thus illustration and description are omitted.

[0046]

As described above, according to the present invention,
This wafer is clamped by the stress that is attracted or pressed from both main surfaces of the semiconductor wafer. Since no stress parallel to the main surface of the wafer is generated, there is no fear of damaging the main surface of the wafer, and the clamping is high. Power is gained,
All of the above-mentioned tasks (1) to (11) have been achieved.

[Brief description of the drawings]

FIG. 1 is a sectional view showing vacuum tweezers as a clamping device according to an embodiment of the present invention.

FIG. 2 is a plan view showing a right half of the holding device of the embodiment.

FIG. 3 is a cross-sectional view showing a state where a semiconductor wafer is sucked by the holding device of one embodiment.

FIG. 4 is a sectional view showing a holding device according to another embodiment of the present invention.

5A and 5B are a sectional view and a plan view showing a conventional vacuum tweezer.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1, 1 '1st suction part 2, 2' 2nd suction part 3 Exhaust path 4 Root part 5 Switch 6, 37 Semiconductor wafer 7 Grasping part 8 Suction part 9, 9 'Side movable part 10 Guide 11, 11' Suction path 12 Suction port 13, 13 'Suction path 14 First suction surface 15 Second suction surface 16 Suction direction 17 Side surface 18 Wafer contact surface 19 Center line 20, 20' Suction direction 21 Column 22, 22 'Suction direction 35, 36 Holding plate 38, 39 Seal member 40 Space 42 Pipe 50 Seal gap 51 Wafer gap 53, 60, 61 Stress

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code Agency reference number FI Technical display location B65G 49/07 B65G 49/07 G

Claims (5)

(57) [Claims] 1. A first method for adsorbing one main surface of a semiconductor wafer.
, A second suction unit for sucking the other main surface of the wafer, and a path through which suction air for suctioning the inside passes, and separating the first and second suction units by a predetermined distance. A semiconductor wafer clamping device, comprising: 2. The semiconductor wafer holding device according to claim 1, wherein said first and second suction portions each have an intake port and an intake path therein. 3. The semiconductor wafer holding device according to claim 1, wherein said support portion has a movable portion which moves by suction pressure in a direction away from a side surface of said semiconductor wafer which is sucked. 4. The semiconductor wafer holding device according to claim 3, wherein said movable portion has elastic mobility in a direction of bringing said first and second suction portions closer to each other by said suction pressure. 5. The semiconductor wafer clamping device according to claim 1, wherein said support portion has a root portion having a dimension larger than an arrangement pitch of said semiconductor wafers.