Method for extrusion molding of sponge brush

Abstract

To provide a method for extrusion molding of a sponge brush, which is capable of continuously extruding a sponge brush having spiral projections on its outer surface from a die by simply injecting a resin thereinto.SOLUTION: There is provided a method for extrusion molding of a sponge brush, including: fixing a die having a spiral molding groove with a square cross section extending along a length direction on its inner circumferential surface into inside of an extrusion die so as not to rotate; continuously injecting a resin material in a molten state from an inlet of the extrusion die; flowing inside of the molding groove of the die; and extruding a sponge brush having a plurality of spiral projections on its outer surface from an outlet of the extrusion die.SELECTED DRAWING: Figure 14

Description

Technical Field

[0001] The present invention relates to an extrusion molding method for a sponge brush, and more particularly to an extrusion molding method for a cylindrical sponge brush having a plurality of spiral protrusions on its outer surface.

Background Art

[0002] The semiconductor chip structure is becoming increasingly miniaturized and multi-dimensional, and chemical, mechanical, polishing, and planarization processes by CMP (Chemical Mechanical Polishing) aiming at wafer planarization are becoming important. In CMP processing, in order to improve the surface cleaning of many particles adhering to the wafer, reduce the cleaning liquid used, and shorten the cleaning time, a sponge brush having spiral protrusions that contact and rotate on the wafer is desired.

[0003] Patent Document 1 shows a sponge brush having granular protrusions on its outer surface. This sponge brush is injection-molded using a cylindrical mold as shown in FIG. 6 of Patent Document 1. Generally, injection molding is costly in manufacturing the mold, and after injecting the molten resin into the mold and cooling it, it is taken out of the mold.

[0004] Patent Document 2 shows that a sponge brush having spiral protrusions on its outer surface is formed by extrusion molding. According to FIG. 13 of Patent Document 2, in order to form spiral grooves, the die part of the extrusion molding is rotated. By rotating the die part with a drive motor, spiral protrusions are continuously extruded and formed.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0006] An object of the present invention is to provide an extrusion molding method for a sponge brush, which can continuously extrude a sponge brush having spiral protrusions on the outer surface from a mold simply by pressing resin.

Means for Solving the Problems

[0007] The extrusion molding method for a sponge brush according to the present invention fixes, without rotation, a die having a spiral and rectangular cross-section molding groove extending along the length direction on the inner peripheral surface inside an extrusion die, continuously presses a molten resin material into the inlet of the extrusion die, allows the resin material to flow inside the molding groove of the die, and extrudes a sponge brush having a plurality of spiral protrusions on the outer surface from the outlet of the extrusion die.

[0008] The extrusion fitting is provided, on the upstream side of the die, with a guide member attached to a mandrel and forming spiral blades for guiding the resin material into the molding groove, and after flowing the resin material along the blades, guiding it to the die.

Effects of the Invention

[0009] According to the present invention, a die having a spiral molding groove on the inner peripheral surface is fixed inside an extrusion die without rotation, a molten resin material is continuously pressed into the inlet of the extrusion die, the inside of the molding groove of the die is allowed to flow, and a sponge brush having a plurality of spiral protrusions on the outer surface is extruded from the outlet of the extrusion die, so that a cylindrical sponge brush can be continuously molded. After molding, through a cooling process and a cutting process, a sponge brush of a predetermined length can be obtained.

[0010] A guide member attached to a mandrel and forming spiral blades for guiding the resin material into the molding groove is provided on the upstream side of the die of the extrusion die, and after flowing the resin material along the blades and then guiding it to the die, the resin material smoothly flows into the spiral groove of the die.

Brief Description of the Drawings

[0011]

Figure 1

Figure 2

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Figure 8

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Figure 13

Figure 14

Embodiments for Carrying Out the Invention

[0012] Hereinafter, with reference to the drawings, the extrusion molding method of the sponge brush according to the present invention will be described in detail. FIGS. 1 to 13 are drawings of the extrusion die, and FIG. 14 is a flowchart of the extrusion molding method of the sponge brush using the extrusion die.

Examples

[0013] Figure 1 is a front view of the extrusion die 100 according to the present invention. The extrusion die 100 consists of a cylindrical socket 1, with a length of about 15 cm on the left and right and a diameter of about 9 cm. The left side of Figure 1 is the inlet side 16 of the extrusion die 100, into which the molten resin material is press-fitted. The right side is the outlet side 17 of the extrusion die 100. The set screw 6 is a screw for fixing the die 2 (described in Figure 6) inserted inside to the socket 1. The dimensions are for one embodiment and are not limited thereto.

[0014] Figure 2 is a left side view of the extrusion die 100 in Figure 1. Figure 2 is a drawing seen from the inlet side 16 of the extrusion die 100. In the guide member mounting holes 12 of the socket 1, there are four blades 7 attached to the mandrel 5.

[0015] Figure 3 is a cross-sectional view taken along the line A-A in Figure 2. Figure 3 is a horizontal cross-sectional view of the extrusion die 100. The extrusion die 100 consists of a die 2 and a guide member 3 provided on the upstream side of the die 2. The guide member 3 has spiral blades 7 attached to the mandrel 5. The die 2 has a spiral forming groove 9 on its inner circumference. The length of the guide part 3 is about 10 cm, and the length of the die 2 is about 5 cm.

[0016] Figure 4 is a cross-sectional view of the socket 1 in Figure 3. It is a drawing of the A-A cross-section in Figure 3 viewed from above, and the die 2 and the guide member 3 are omitted from the illustration. There is a guide member mounting hole 12 on the left side and a die mounting hole 8 on the right side. The guide member 3 is inserted into the guide member mounting hole 12, and the die 2 is inserted into the die mounting hole 8. In the portion of the socket 1 where the die 2 is inserted, there are screw holes 18 drilled in the socket 1. Three screw holes 18 are provided on the outer circumference of the socket 1.

[0017] Figure 5 is a front view of the guide member 3. Four blades 7 are spirally attached to the mandrel 5 on the guide member 3. The attachment is by welding. Since the mandrel 5 is also inserted into the die 2, it has the same length as the socket 1. Because the blades 7 are spirally twisted, when the molten resin material 11 is press-fitted from the inlet side 16, the resin material 11 is guided to wrap around the mandrel 5 and can be fed into the die 2.

[0018] Figure 6 is a front view of the die 2. The die 2 is cylindrical, and three screw receiving recesses 10 are provided at equal intervals on the outer periphery. The die 2 is fixed to the socket 1 by three set screws 6. After the die 2 is fixed to the socket 1, the guide member 3 is inserted into the socket 1.

[0019] Figure 7 is a right side view of the die 2. Twelve forming grooves 9 are provided on the inner periphery of the through hole 15. The angle between the forming groove 9 and the forming groove 9 is about 30°. Here, the diameter connecting the bottoms of the forming grooves 9 is about 50 mm, and the diameter connecting the tops of the forming grooves 9 is about 40 mm. The width of the forming groove 9 is about 5.5 mm. The width of the forming groove 9 is not limited to this. The forming groove 9 becomes the protrusion 21 of the sponge brush 100 formed by extrusion molding. On the inner peripheral surface of the die 2, a spiral and cross-sectionally square forming groove 9 extending along the length direction is formed.

[0020] Figure 8 is a view showing the axial twist of the forming groove 9. As shown by the dotted line, the forming groove 9 is twisted in a spiral shape and provided on the inner periphery of the die 2.

[0021] Figure 9 is a view showing the circumferential twist of the forming groove 9. Looking at the forming groove 9 of the die 2 in Figure 8, it is twisted clockwise by nearly 90°.

[0022] Figure 10 is a front view of the sponge brush 20. The sponge brush 20 is cylindrical, about 20 cm long and about 5 cm (= 50 mm) in diameter. It has a plurality of, specifically 12, spiral and cross-sectionally square protrusions 21 on the outer periphery. After being formed by the extrusion mold 100, it goes through a cooling process and a cutting process to become the shape shown in Figure 10.

[0023] Figure 11 is a right side view of the sponge brush 20. There is a through hole 22 in the center, and 12 protrusions 21 are provided on the outer periphery. The angle between the protrusion 21 and the protrusion 21 is about 30°. The outer periphery is 157 mm (= 3.14 × 50 mm), the width of the protrusion 21 is about 5.5 mm, and the interval between the protrusion 21 and the protrusion 21 is about 7.6 mm.

[0024] FIG. 12 is a view showing the axial twist of the protrusion 21. As shown in FIG. 12, when focusing on one of the plurality of protrusions 21, it is twisted in a spiral shape. The same applies to the other protrusions 21.

[0025] FIG. 13 is a view showing the circumferential twist of the protrusion 21. When focusing on one of the plurality of protrusions 21 shown in FIG. 12, it is twisted by about 270°. The same applies to the other protrusions 21.

[0026] FIG. 14 is a flowchart of the extrusion molding method of the sponge brush 20 according to the present invention. S1 is a step of flowing and guiding the continuously press-fitted resin material 11 along the guide member 3 having the spiral blades 7. S2 is a step of extrusion-molding a cylindrical sponge brush provided with a plurality of protrusions 21 on the outer circumference by a die 3 having a spiral molding groove 9 formed on the inner circumference. By the two-step extrusion molding, a continuous sponge brush 20 can be molded.

Industrial Applicability

[0027] The present invention is suitable as an extrusion molding method capable of continuously extrusion-molding a sponge brush having spiral protrusions on the outer surface by press-fitting a resin.

Explanation of Reference Numerals

[0028] 1 Socket 2 Die 3 Guide Member 4 Forming Portion 5 Mandrel 6 Set Screw 7 Blade 8 Die Mounting Hole 9 Molding Groove 10 Screw Receiving Recess 11 Resin Material 12 Guide Member Mounting Hole 15 (Die's) Through Hole 16 Inlet Side 17 Outlet Side 18 Screw Hole 20 Sponge Brush 21 (Sponge Brush's) Protrusion 22 Through-hole (of the sponge brush) 23 Valley 100 Extrusion die

Claims

1. A die having a spiral and cross-sectionally angular forming groove extending along the length direction on the inner peripheral surface is fixed inside the extrusion mold so as not to rotate, and a molten resin material is continuously pressed into the inlet of the extrusion mold, flows through the inside of the forming groove of the die, and a sponge brush having a plurality of spiral protrusions on the outer surface is extruded from the outlet of the extrusion mold. A method for extrusion molding of a sponge brush, characterized by the above.

2. The extrusion fitting is provided with a guide member attached to a mandrel on the upstream side of the die, the guide member forming spiral blades for guiding the resin material into the forming groove, and after flowing the resin material along the blades, guiding it to the die. The method for extrusion molding of a sponge brush according to claim 1, characterized by the above.

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