JP4186400B2 - Shot blasting method and apparatus - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a shot blasting method and apparatus for a pellicle frame or the like of a pellicle apparatus used for transferring an IC or LSI circuit wiring diagram to a lightweight workpiece, for example, a semiconductor substrate.
[0002]
[Prior art]
In a transfer device that exposes the IC or LSI circuit wiring diagram drawn on the hard glass surface and transfers it to the semiconductor substrate, if the dust is attached to the original drawing of the circuit wiring drawing, the transferred wiring diagram is clear. The wiring may be short-circuited. As a countermeasure, dust is prevented from adhering by covering the entire original surface of the circuit wiring diagram with a pellicle in which a light-transmitting pellicle film is attached to the pellicle frame. Such a pellicle will be described below with reference to the drawings.
[0003]
7A and 7B show the photoresist mask 1 and the pellicle 2. FIG. 7A is a sectional view of the photoresist mask 1 with the pellicle 2 attached thereto, FIG. 7B is a sectional view of the pellicle 2, and FIG. FIG.
[0004]
As shown in FIG. 7A, the photoresist mask 1 has a hard glass 3 which is a transparent substrate, and a circuit wiring diagram 4 such as IC or LSI is drawn on one surface of the hard glass 3. A pellicle 2 is adhered to the photoresist mask 1 so as to cover the circuit wiring diagram 4 side.
[0005]
As shown in FIG. 7B, the pellicle 2 is formed by sticking a light-transmitting pellicle film 5 to a pellicle frame 6 and adheres to the photoresist mask 1 so as to cover the entire original drawing of the circuit wiring diagram 4. Is done. The size of the pellicle frame 6 corresponds to the size of the photoresist mask 1. For example, the length of the diagonal line is 25 to 300 mm and the height is 2 to 10 mm in many cases. In FIG. 7B, reference numeral 7 indicates the height direction of the pellicle frame 6.
[0006]
When the pellicle 2 is attached to the photoresist mask 1 by adhesion, the pellicle 2 with the adhesive 9 is peeled off from the adhesive protective film 8 previously stretched on the pellicle 2, and the circuit wiring diagram 4 shown in FIG. Cover and paste the entire original drawing. Thus, on the circuit wiring diagram 4 side of the photoresist mask 1 to which the pellicle 2 is adhered, dust is blocked by the pellicle film 5 and does not adhere to the surface of the circuit wiring diagram 4. Even if dust adheres to the pellicle film 5, the dust is out of focus in the circuit wiring diagram 4 formed on the surface of the semiconductor substrate by the light from the external light source that has passed through the lens. The schematic circuit wiring diagram 4 is transcribed.
[0007]
In this way, since the pellicle film 5 is stuck to the pellicle frame 6, an aluminum alloy having high strength such as JIS A7075, 6061, 5052 is used.
[0008]
Incidentally, in the transfer step of the circuit wiring diagram, shot blasting is performed on the entire surface of the pellicle frame 6 in order to prevent reflection of light from the light source and obtain a clear transfer wiring diagram 4.
[0009]
In the above-described shot blasting performed on the entire surface of the pellicle frame 6, gripping traces of the processing jig are not allowed. Therefore, conventionally, since the pellicle frame is a small, lightweight, thin-walled frame-shaped member, the operator has held it in hand, that is, shot blasting is performed manually.
[0010]
[Problems to be solved by the invention]
By the way, with the development of semiconductor-related industries, the demand for pellicle frames has increased, and there has been a need for a shot blasting method that does not rely on manuals.
Since heavy workpieces do not move due to the shot impact of shot media, if shot media is projected while rotating the workpiece, shot blasting is performed uniformly regardless of the manual. be able to.
[0011]
However, in order to perform shot blasting on a light workpiece without using a manual, it is necessary to grip and fix the workpiece so that the workpiece does not move due to the impact impact of shot media. When the work piece is gripped and fixed in this manner, the work piece has a grip mark, which makes it difficult to uniformly process the work piece.
[0012]
The present invention relates to a shot blasting method capable of uniform and stable shot blasting without a grip mark on a light-weight workpiece, particularly a small, thin-walled, lightweight frame-shaped member such as an aluminum frame for a pellicle. And an apparatus for the same.
[0013]
[Means for Solving the Problems]
As a result of performing various processing tests in the above-described shot blasting method, the inventors have rotated the pellicle frame in a horizontal plane, projected shot media onto the frame from obliquely above the pellicle frame, and projected the media. The present invention has been completed on the assumption that a uniform and stable shot blasting process can be performed on the entire surface of the pellicle frame as much as the conventional manual method by moving the frame with an impact force.
[0014]
That is, according to the present invention, a rectangular pellicle frame is placed in an unconstrained state on a work table having a substantially horizontal portion formed by bending a wire, and the work table is rotated in a substantially horizontal plane while obliquely above the pellicle frame . characterized in that the projecting the shot media against the pellicle frame, by moving the upper work platform the pellicle frame of the shot media to the projection direction by the projection impact force of the shot media, performs processing of shot blasting for the pellicle frame Is a shot blasting method.
[0015]
According to the above method, since the pellicle frame is only placed in a non-constrained state on the work table, when projecting a shot media obliquely from above of the pellicle frame, a pellicle frame is subjected to projection impact force of the shot media Move on the worktable in the shot media projection direction. At the same time, the shot medium is projected while the pellicle frame rotates as the work table rotates in a substantially horizontal plane. As a result, it is possible to perform shot blasting on a plurality of surfaces of the pellicle frame at the same time without making a trace of the jig by simply projecting shot media once for a predetermined time.
[0016]
Further, the present invention is characterized in that projecting the shot media projected onto pellicle frame, toward the side surface and the inner surface and the upper side and the outer faces of the pellicle frame.
[0017]
Furthermore, the present invention provides a rotary table that rotates in a substantially horizontal plane, a substantially horizontal portion that is formed by bending a wire on the rotary table, and in which a rectangular pellicle frame is placed in an unconstrained state, and for preventing the pellicle frame from falling. a worktable having a stopper, provided on the diagonally upper side of the worktable, and a projection nozzle for projecting shot media pellicle frame on the work table, the pellicle frame with the projection impact force of the shot media projected from the projection nozzle Is a shot blasting apparatus that performs a shot blasting process on a pellicle frame by moving a workpiece on a work table in a shot media projection direction.
[0018]
DETAILED DESCRIPTION OF THE INVENTION
Next, embodiments of the present invention will be described with reference to the drawings.
A workpiece, for example, a pellicle frame is made from a hollow extruded material or a plate material corresponding to the dimension of the pellicle frame.
When a pellicle frame is manufactured from a hollow extruded material, a pellicle frame shape is formed by cutting a ring in the height direction (h in FIG. 7) of the pellicle frame and performing machining such as cutting and grinding. The obtained pellicle frame is subjected to shot blasting after machining for the purpose of improving the adhesion of the anodized film, eliminating fine scratches, and preventing light reflection.
[0019]
In shot blasting, granular or irregular shot media is projected onto the surface of a workpiece with a predetermined pressure (compressed air pressure) to physically change the surface shape of the workpiece. The shot media used at this time is not particularly limited, but in a pellicle frame using an aluminum alloy having high strength, granular stainless steel beads have a high processing rate and are also preferable in terms of durability of the media. Inexpensive. The selection conditions for the shot media are not limited, but may be appropriately selected from the range of the following selection conditions.
Shot media condition material SUS304, SUS420, glass shape granular, lump size # 30-300 (mesh)
[0020]
In addition, as for the projection condition, an arbitrary condition range set relatively according to the surface state of the target processed workpiece (pellicle frame) is taken, but is limited to a certain range depending on the specifications of the processing machine. . These processing conditions are not limited, but may be appropriately selected from the following processing conditions.
Shot blasting projection conditions Projection pressure 0.1 to 0.5 MPa
Projection distance 10-400mm
Projection angle 10-80 degrees
Pellicle frames that have undergone shot blasting are conventionally anodized for the purpose of surface hardening, and further black-dyed for the purpose of preventing reflection of light. Finally, the aim is to improve corrosion resistance and dye retention and hardening. The sealing process is completed.
[0022]
Next, a shot blasting apparatus according to the present invention will be described.
1 and 2 show a shot blasting apparatus according to the present invention. FIG. 1 is a plan view and FIG. 2 is a front view thereof. A circular turntable 11 is provided, and the turntable 11 is rotationally driven in a substantially horizontal plane by a motor (not shown). On the rotary table 11, thin wire-like work tables 12 are provided at four locations. The work table 12 is made by bending a steel wire having a diameter of 1.0 mm covered with a Teflon tube having an outer diameter of 3.0 mm at a position of about 50 mm on the rotary table 11.
[0023]
The shape requirement necessary for the work table 12 is that the pellicle frame 6 can be prevented from jumping out of the work table 12 due to the portion (receiving surface) that can hold the pellicle frame 6 horizontally and the external force of the shot media due to projection. It has a simple receiving part (stopper). At this time, since it is indispensable for the pellicle frame 6 to be held that the projection surface does not become a blind spot on the work table 12, a method of directly fixing the surface of the pellicle frame 6 is inappropriate. Therefore, as shown in FIG. 3, the work table 12 according to the present embodiment is formed with a 12A portion as a receiving surface and a 12B portion as a stopper.
[0024]
Both ends of the wire-like work table 12 are inserted into the locking member 13 and attached to the locking member 13 with screws (not shown). The locking member 13 is fixed to the work base 14, and the work base 14 is attached to the rotary table 11 with a bolt (not shown). As a result, the work table 12 is firmly fixed on the rotary table 11.
[0025]
The height H of the stopper 12B is not particularly defined as long as it is approximately the same as the height of the pellicle frame 6 (2.5 to 6 mm). At this time, in order to prevent the occurrence of a shadow (dead angle) on the pellicle frame 6 due to the shot media being projected obliquely from above, the work table stopper located near the pellicle frame 6 and the projection nozzle moved by the projection impact force of the shot media. The interval (D) of 12B is as follows. When the stopper height is H and the projection angle is θ (degrees),
D> H × (tan θ) ⁻¹
Need to be satisfied. In the present embodiment, the movement of the pellicle frame 6 satisfies the above relationship during processing (the relationship between D and H).
[0026]
The steel wire forming the skeleton of the work table 12 is covered with a Teflon tube, which is intended to prevent scratches on the pellicle frame 6 due to contact sliding between the work table 12 and the pellicle frame 6. It is what. Therefore, the material for covering the steel wire is not limited to the Teflon tube as long as the sliding property of the pellicle frame 6 is improved and the material used is softer than the material used for the pellicle frame 6.
[0027]
FIG. 4 is a perspective view showing the rotary table 11 and the work bases 12 provided at four locations on the rotary table 11. In FIG. 4, the work table support and the locking member are omitted. As shown in the figure, projection nozzles 15 and 16 for projecting shot media onto a pellicle frame on the work table 12 are installed obliquely above the rotary table 11. Here, the projection nozzles 15 and 16 are installed at the same projection distance to the pellicle frame. Three projection nozzles can be installed. When three nozzles are installed, the third projection nozzle is arranged vertically above the pellicle frame to project shot media onto the upper surface side. In FIG. 4, the hatched portion indicates the movement range of the pellicle frame 6.
[0028]
In the above configuration, when shot blasting is performed on the pellicle frame, first, as shown in FIG. 5A, the pellicle frame 6 is placed evenly and unconstrained on all four work bases 12. To do. Next, as shown in FIG. 5B, the rotary table 11 is rotated in the direction a, and the shot media S is projected from the projection nozzles 15 and 16. Then, since the pellicle frame 2 is in an unconstrained state, the pellicle frame 2 moves on the work table 12 in the projection direction of the shot medium S (the direction away from the projection nozzles 15 and 16) by the projection impact force of the shot medium S. Stops by hitting the stopper 12B. At this time, the corner of the pellicle frame 2 is fitted between the two stoppers 12B of the work table 12.
[0029]
While the rotary table 11 rotates and advances 90 degrees from the state shown in FIG. 5B to become as shown in FIG. 5C, the pellicle frame 2 is constantly shot by the shot medium S projection pressure. It is pressed against the stopper 12B in the S projection direction. Also at this time, as shown in FIG. 5C, the next corner of the pellicle frame 2 fits between the two stoppers 12 </ b> B of the next work table 12.
[0030]
Further, since the projection nozzles 15 and 16 are disposed obliquely above the pellicle frame 6, it is possible to simultaneously project shot media onto the inner side surface, the outer side surface, and the upper surface of the pellicle frame 6 as the turntable 11 rotates. . That is, it is possible to project shot media onto the inner surface and the upper surface of the pellicle frame 6 by the projection nozzle 15 and to the outer surface and the upper surface of the pellicle frame 6 by the projection nozzle 16, respectively. As a result, the processing time for shot blasting can be shortened.
[0031]
If the third projection nozzle is arranged vertically above the pellicle frame 6 and the shot media is projected from the projection nozzle to the pellicle frame, the upper surface of the pellicle frame 6 is further smoothed. When the pellicle frames are stacked and transported, there is no possibility of damaging the lower surface of the stacked upper pellicle frame.
[0032]
According to the present embodiment, since the work table 12 is composed of a thin wire, secondary projection due to reflection of the projected shot media can be prevented and the contact area with the pellicle frame 6 is minimized, so that the shot media The pellicle frame 6 can be easily moved by the projected impact force. This prevents shot media from rebounding (secondary projection) at the time of projection, and enables uniform shot blasting on each surface of the pellicle frame 6 without unevenness. Further, when the installation height of the work table 12 on the rotary table 11 is about 50 mm, it is possible to more effectively prevent the shot media from bouncing back.
[0033]
【Example】
A billet of JIS A7075 alloy component was produced by a DC casting method and homogenized, and then the billet was cut into a predetermined length and extruded to obtain a rectangular hollow extruded material. Thereafter, the tempering condition T651 shown in JIS H0001 was applied. Further, a pellicle frame having an outer dimension of 149 mm × 122 mm × 5.8 mm having a frame shape as shown in FIG. 7 was produced by cutting (round cutting) and machining. Next, shot blasting was performed on these pellicle frames.
[0034]
Here, a system configuration for automatically performing shot blasting will be described. As shown in FIG. 6, a rotary hand device 20 is installed, a pellicle frame supply device 21 is disposed on one side of the rotary hand device 20, and a pellicle frame transfer device 22 and a transport device 23 are disposed on the other side. 24 is arranged. A shot blasting device 25 according to the present invention is installed on the side of the rotary hand device 20.
[0035]
The rotary hand device 20 is provided with a telescopic arm 20A, and a hand portion 20B for gripping the pellicle frame 6 is provided at the tip of the arm 20A. The hand unit 20B also has a function of inverting the upper and lower surfaces of the gripped pellicle frame. Further, the rotary hand device 20 rotates 180 degrees between the pellicle frame supply device 21 and the pellicle frame transfer device 22 as indicated by a two-dot chain line in the figure.
[0036]
The shot blasting device 25 has a door 25A on the side close to the rotary hand device 20, and the above-described rotary table 11 is provided therein.
[0037]
In the above-described configuration, a plurality of pellicle frames 6 to be shot blasted are inserted into the pellicle frame supply device 21 from the direction of the arrow b in the figure, and are set to overlap horizontally in the device. The rotary hand device 20 extends the arm 20A, and grips the pellicle frame 6 one by one by the hand portion 20A at the tip. When the pellicle frame 6 is gripped, the rotary hand device 20 slightly raises the entire arm 20A and separates the gripped pellicle frame 6 from other pellicle frames. In this state, after rotating the arm 20A, the rotary hand device 20 rotates 90 degrees clockwise and stops to extend the arm 20A. At this time, the door 25A of the shot blasting device 25 is open, and the pellicle frame 6 gripped by the hand portion 20B is conveyed to the position just above the rotary table 11 through the door 25A. Then, the rotary hand device 20 slightly lowers the entire arm 20 </ b> A and places the pellicle frame 6 on the four work tables 12 (see FIG. 1 and the like) on the rotary table 11. When the pellicle frame 6 is placed on the work table 12, the rotary hand device 20 reduces the arm 20A, and the shot blasting device 20 closes the door 25A. Thereby, preparation for shot blasting is completed.
[0038]
Shot blasting is performed by projecting shot media onto the pellicle frame 6 as described above. At this time, preferably, in the shot blasting device 25, the rotation of the turntable 11 is started before the start of shot media projection (processing start). The reason why the rotation of the turntable 11 is started prior to the start of shot media projection is to prevent local projection (unevenness) onto the pellicle frame 6 at the start of shot media projection. In this embodiment, the rotation of the turntable 11 is started 3 seconds before the shot media projection is started. The shot media is continuously projected for a predetermined period of time, and then the rotation of the turntable 11 is stopped. The reason why the rotation stop of the turntable 11 comes after the end of projection is to prevent local projection (unevenness) on the pellicle frame 6 at the end of projection, as in the case of the start of rotation. In this embodiment, the rotation of the turntable 11 was stopped 3 seconds after the end of projection. With the above operation, the shot blast processing of the three surfaces of the inner surface, the outer surface, and one upper surface (end surface) of the pellicle frame 6 is completed.
[0039]
When the above shot blasting is completed, the shot blasting device 25 opens the door 25A, and the rotary hand device 20 extends the arm 25A. Thereafter, the rotary hand device 20 grips the pellicle frame 6 on the work table 12 with the hand unit 20B, slightly raises the entire arm 25A to separate the pellicle frame 6 from the work table 12, and moves the hand unit 20B around its central axis. And the upper and lower surfaces of the pellicle frame 6 are reversed. When the upper surface and the lower surface are reversed, the rotary hand device 20 lowers the arm 20A and places the pellicle frame 6 on the work table 12 again. Then, the hand portion 20B is retracted, the door 25A of the shot blasting device 25 is closed, and shot blasting is performed in the same manner as described above.
[0040]
Through the above operation, shot blasting could be automatically performed on all the inner and outer surfaces and both end surfaces of the pellicle frame 6.
[0041]
Here, used shot media selection conditions and shot blast projection conditions are shown below.
(1) Shot media condition material SUS304
Shape Granular size # 300 (mesh)
(2) Shot blasting projection condition Number of projection nozzles 2 Projection pressure 0.4 MPa
Projection distance 230mm
Projection angle 25 degrees Projection time 24 seconds Table rotation time 30 seconds Table rotation speed 18 degrees / second [0042]
Next, the pellicle frame 6 that has been shot blasted is discharged from the shot blasting apparatus 20. First, in FIG. 6, after processing is completed, the door 25A of the shot blasting device 25 is opened, and the rotary hand device 20 extends the arm 20A to grip the pellicle frame 6 on the work table 12. When the rotary hand device 20 grips the pellicle frame 6, the rotary hand device 20 shortens the arm 20A, and further rotates 90 degrees clockwise and stops. Then, the rotary hand device 20 extends the arm 20 </ b> A and transfers the pellicle frame 6 to the pellicle frame transfer device 22.
[0043]
A pellicle frame storage case is supplied to the pellicle frame transfer device 22 from the transport device 23, and the pellicle frame 6 delivered from the rotary hand device 20 is stored in the storage case. The storage case in which the pellicle frame 6 is stored is transferred from the pellicle frame transfer device 22 to the transfer device 24 and is transferred to a predetermined stock location by the transfer device 24. In the drawing, the arrows on the transfer device 23 and the pellicle frame transfer device 22 indicate the transfer direction of the storage case, and the arrow on the transfer device 24 indicates the transfer direction of the storage case after the pellicle frame is stored.
[0044]
When the transfer of the pellicle frame 6 to the pellicle frame transfer device 22 is completed, the rotary hand device 20 rotates 180 degrees horizontally counterclockwise and is taken out from the pellicle frame supply device 21 to the next pellicle frame and shot. Prepare for blasting.
[0045]
【The invention's effect】
As described above, according to the present invention, a uniform and stable shot blasting process can be performed on a lightweight workpiece without a grip mark.
[Brief description of the drawings]
FIG. 1 is a plan view of a main part of a shot blasting apparatus according to the present invention.
FIG. 2 is a front view of FIG. 1;
FIG. 3 is a perspective view of a work table.
FIG. 4 is a perspective view of a shot blasting apparatus according to the present invention.
FIGS. 5A and 5B show the processing by the shot blast processing apparatus according to the present invention, in which FIG. 5A shows a state where the pellicle frame is set, and FIGS. 5B and 5C show the processing while rotating the rotary table. FIG.
FIG. 6 is a system configuration diagram that automatically performs shot blasting.
FIGS. 7A and 7B show an embodiment of a pellicle frame, where FIG. 7A is a cross-sectional view showing a state in which a pellicle frame is attached to a transparent substrate, FIG. 7B is a cross-sectional view of the pellicle frame, and FIG. It is a top view.
[Explanation of symbols]
6 Pellicle frame 11 Rotating table 12 Work table 12A Receiving surface 12B Stopper 13 Locking member 14 Work table receiving 15, 16 Projection nozzle 20 Rotating hand device 20A Arm 20B Hand unit 21 Pellicle frame supply device 22 Pellicle frame transfer device 23, 24 Transport device 25 Shot blasting device 25A Door

Claims (3)

Placing a rectangular pellicle frame on a work platform having a substantially horizontal portion formed by bending a wire in a non-constrained state, while rotating the worktable in a substantially horizontal plane, said pellicle frame obliquely from above of the pellicle frame characterized in that projecting the shot media, the said pellicle frame by projection impact force of the shot media shot media to the projection direction by moving the work platform above performs processing of shot blasting for the pellicle frame relative to Shot blasting method. In the shot blasting method according to claim 1, the shot media for projecting to the front Symbol pellicle frame, characterized in that projecting toward the side surface and the inner surface and the upper side and the outer faces of the said pellicle frame Shot blasting method. A rotary table that rotates in a substantially horizontal plane, a wire formed on the rotary table by bending, a substantially horizontal portion on which a rectangular pellicle frame is placed in an unconstrained state, and a stopper for preventing the pellicle frame from falling a work table, disposed obliquely above the workpiece table, and a projection nozzle for projecting shot medium to the pellicle frame on the work table, the pellicle in projection impact force of the shot media projected from the projection nozzle frame wherein by moving the upper work platform the shot media to the projection direction, the shot blasting machine, which comprises carrying out the processing of shot blasting for the pellicle frame.

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