CN115742049A

CN115742049A - Multi-strand combined rotary twisted cutting wire

Info

Publication number: CN115742049A
Application number: CN202211537773.4A
Authority: CN
Inventors: 朱惠冲
Original assignee: Individual
Current assignee: Individual
Priority date: 2022-12-01
Filing date: 2022-12-01
Publication date: 2023-03-07

Abstract

The invention discloses a multi-strand combined rotary stranded cutting wire which comprises two or more than two tungsten cutting filaments, wherein the multiple tungsten cutting filaments are spirally wound and stranded with one another to form the cutting wire, and a plurality of annular pressing surfaces are arranged on the outer surface of the cutting wire. According to the invention, a plurality of tungsten cutting filaments are mutually spirally wound and twisted to form the cutting filament, and after the cutting filament is spirally wound and twisted, the integral tensile strength is greatly improved; the tensile strength of the spirally wound and stranded cutting wire is greater than that of a single tungsten cutting wire under the condition of the same overall diameter. From the perspective of raw materials, the invention improves the tensile strength per unit cross section. Furthermore, the outer surface of the cutting wire is provided with the annular pressing surface, and the part with the highest projection of the outer surface after the spiral is compressed to form the annular pressing surface, so that the concave-convex degree of the whole outer surface is reduced, scratches formed on the silicon surface during cutting are reduced, and the cut surface is smoother.

Description

Multi-strand combined rotary twisted cutting wire

Technical Field

The invention relates to the technical field of cutting wires, in particular to a multi-strand combined rotary stranded cutting wire especially used for cutting silicon wafers.

Background

China accelerates the industrialization process of new technology of third-generation new semiconductor materials represented by silicon carbide and gallium nitride, and various products from daily use to industrial manufacturing and military industry are gradually updated and expanded, the silicon carbide is ubiquitous in application, the application is very wide, and the demand of intelligent chips is astronomical numbers. The high-end silicon carbide raw material bar for producing the chip must be cut into thin pieces for use, and the silicon carbide is a very hard and compact semiconductor material, is very expensive, and has very low cutting speed and efficiency. The production mode that present market tradition adopted is that carbon steel wire drives mortar abrasive cutting, and the cutting mode of carbon steel wire as the cutting consumptive material brings the defect such as finished product one time yields is low, speed is slow, finished product surface has the stripe, can not satisfy the requirement of carborundum precision cutting completely.

The inventor has invented a high-performance rare earth alloy tungsten cutting wire, the surface of which is formed with tree-shaped concave resistors, which can improve the binding force of a metal coating and a tungsten wire, ensure the consolidation quality of diamond particles, and prolong the service life of the cutting wire on the basis of ensuring enough tensile strength. For the specific structure, the inventor applies for the Chinese patent application with publication number CN114480936A at 24/2/2022. After the product is released to the market, the product is widely praised by users. However, in the use process, the following improvement spaces still exist:

with the increasing price of silicon wafers, higher requirements are put on the material loss ratio in the cutting process, and experiments show that the thinner the cutting line is, the lower the material loss is, so that the diameter of the cutting line needs to be made smaller. The diameter of the cutting line becomes smaller with the accompanying problem that the tensile strength is reduced and the life is shortened, so that it is required to improve the above-mentioned cutting line to ensure a certain tensile strength while reducing the diameter of the cutting line.

Disclosure of Invention

In order to overcome the defects of the prior art, the multi-strand combined rotary stranded cutting wire is small in diameter, high in tensile strength and long in service life.

The technical scheme adopted by the invention for solving the technical problem is as follows:

the multi-strand combined rotary twisted cutting wire comprises two or more tungsten cutting filaments, the multiple tungsten cutting filaments are mutually spirally wound and twisted to form the cutting wire, and a plurality of annular pressing surfaces are arranged on the outer surface of the cutting wire.

In the invention, the outer surface of the cutting wire is provided with a spiral chip removal groove for removing chips.

In the invention, diamond powder particles are arranged on the outer surface of the cutting wire.

In the present invention, the diameter of a single strand of tungsten cutting filament is between 0.015mm and 0.15 mm.

In the present invention, the single strand tungsten cutting filament per cm has a helical twist angle of between 3600 ° and 7200 °.

In the present invention, the cutting wire has a circular cross section.

In the invention, the cross section of the cutting wire is a regular polygon.

The invention has the beneficial effects that: according to the invention, a plurality of tungsten cutting filaments are mutually spirally wound and twisted to form the cutting filament, and after the cutting filament is spirally wound and twisted, the integral tensile strength is greatly improved; the tensile strength of the spirally wound and stranded cutting wire is greater than that of a single tungsten cutting wire under the condition of the same overall diameter. From the raw material perspective, the present invention increases the tensile strength per unit cross section.

Furthermore, the outer surface of the cutting wire is provided with the annular pressing surface, and the part with the highest projection of the outer surface after the spiral is compressed to form the annular pressing surface, so that the concave-convex degree of the whole outer surface is reduced, scratches formed on the silicon surface during cutting are reduced, and the cut surface is smoother.

Furthermore, after the multiple tungsten cutting filaments are spirally wound and twisted, a chip removal groove is reserved between the adjacent tungsten cutting filaments, the chip removal groove not only facilitates the flowing of chips during cutting and reduces scratches on the surface of the silicon, but also can play a role in heat removal and reduce the temperature generated during cutting. Under the mortar cutting environment, the device can drive larger mortar flow, thereby improving the cutting speed.

Drawings

The invention is further illustrated by the following figures and embodiments:

FIG. 1 is a schematic structural diagram according to a first embodiment;

FIG. 2 is a top view of the first embodiment;

FIG. 3 is a schematic view of a processing operation according to an embodiment;

FIG. 4 is a schematic structural view of the working mold of FIG. 3;

FIG. 5 is a schematic structural diagram of the second embodiment;

FIG. 6 is a front view of the second embodiment;

FIG. 7 is a top view of the second embodiment.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

In the description of the present invention, it should be noted that the terms "upper", "lower", "inner", "outer", "left", "right", "top/bottom", and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, which are only for convenience in describing the present invention and simplifying the description, but do not indicate or imply that the referred device or element must have a specific orientation, be constructed in a specific orientation, and be operated, and thus, should not be construed as limiting the present invention. Furthermore, the terms "first," "second," and the like are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.

In the description of the present invention, it should be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "disposed," "sleeved/connected," "connected," and the like are to be construed broadly, e.g., "connected," which may be fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art.

The first embodiment is as follows:

referring to fig. 1 to 4, the multi-strand merged rotary twisted cutting wire provided in this embodiment includes two or more tungsten cutting filaments 1, the multiple tungsten cutting filaments 1 are twisted and twisted with each other in a spiral winding manner to form the cutting wire, and the outer surface of the cutting wire is provided with a plurality of annular pressing surfaces 2. In this embodiment, the tungsten cutting filament 1 is provided with three strands, and the diameter of the overall cutting filament is twice that of the single-strand tungsten cutting filament 1. The diameter of the single-strand tungsten cutting filament 1 is between 0.015mm and 0.15mm, preferably 0.04mm, after subsequent processing, the diameter of the whole cutting filament is only 0.075mm, the tensile strength and the service life of the whole cutting filament are better than those of the single-strand tungsten cutting filament with the diameter of 0.075mm, and the whole cutting filament is only half of the existing steel wire with the diameter of 0.15mm, so that the cutting seam is smaller, the yield is higher than 15%, and the raw material loss rate is greatly reduced. According to the method, the unit price of the existing silicon carbide wafer with the thickness of 0.68mm is 6000 yuan/wafer, the loss of one seam is 0.15mm, and the loss of one seam is 0.075mm, so that one silicon carbide raw material can be cut into a plurality of silicon carbide pieces or even more than ten pieces on the original basis, and the silicon carbide wafer with the value of ten thousand yuan can be produced.

In the embodiment, the tungsten cutting filament 1 is a high-performance rare earth alloy tungsten cutting wire, the tungsten cutting filament 1 is made of a material synthesized by 99.75-99.15 wt% of tungsten and 0.25-0.85 wt% of rare earth, and the rare earth contains more than 99.99 wt% of lanthanum; the specific forming process and structure can refer to the chinese patent application publication No. CN114480936A filed by the present inventor at 24/2/2022, and will not be described in detail herein.

In the present embodiment, the annular pressing surface 2 is formed by pressing and cutting an annular pressing and cutting mold 4 made of tungsten steel or CVD diamond, and as shown in fig. 3 and 4, a pressing and cutting hole 40 is formed in the middle of the annular pressing and cutting mold 4. The front section of the pressure cutting hole is an inlet area 41 with a greatly reduced diameter, and the opening angle of the inlet area 41 is 60-90 degrees. The guide zone 41 is followed in turn by a reduced diameter lubrication zone 42 and a compression zone 43, the opening angles of the lubrication zone 42 and the compression zone 43 being 30 ° to 40 ° and 12 ° to 24 °, respectively. The rear section of the compression area 43 is a sizing area 44 with the same diameter, and the sizing area 44 is smaller than the diameter of the cutting wire formed by spirally winding and twisting the three tungsten cutting filaments 1. The guide zone 41 is followed in turn by a safety angle 45 and an exit zone 46 of increasing diameter, the opening angles of the safety angle 45 and the exit zone 46 being 10 ° and 60 ° -90 °, respectively. In the press cutting, the annular press cutting die 4 needs to be placed into a high-temperature furnace for heating, the temperature in the furnace is 350 ℃, and the die temperature is close to 400 ℃. The ratio of the diameter after press cutting to the diameter before press cutting is 84-92%: 1, preferably 92%: the speed of the press-cutting is preferably 50 to 150mm/min. The part with the highest surface protrusion is flattened or cut off through the annular pressing and cutting die 4, so that the annular pressing and cutting die forms an annular pressing surface 2, the flatness of the outer surface of the whole cutting wire is ensured, scratches formed on the silicon surface during cutting are reduced, and the cut surface is smoother. The finished product after cutting has high surface finish, is not easy to generate cutting stripes, reduces the grinding, polishing and reprocessing difficulty, has high yield at one time and superior quality, and can meet the processing requirements of high stability, high precision, high quality and ultra-thinness.

Meanwhile, after ring pressing, the three tungsten cutting filaments 1 are wound and twisted spirally more tightly, and the structure is firmer. Meanwhile, the high-temperature die can eliminate the internal stress when the tungsten cutting filaments 1 are twisted in a spiral mode, so that the internal structure is more stable and is not easy to deform. In this embodiment, the cross section of the cutting hole is circular, and the cross section of the whole cutting wire after cutting is also circular. Of course, here, the cross section of the cutting hole may also be a regular polygon, so that the cross section of the whole cutting wire after press cutting is also a regular polygon to cope with different cutting environments.

As preferred embodiment, after three strands of tungsten cutting filaments 1 are spirally wound and twisted, spiral chip removal grooves 3 are reserved between adjacent tungsten cutting filaments 1, the chip removal grooves 3 not only facilitate the flow of chips during cutting and reduce scratches on the silicon surface, but also play a role in heat removal, reduce the temperature generated during cutting and ensure better cutting effect. The surface of the traditional cutting wire is smooth, so that cutting in mortar is needed, or diamond powder is added on the surface of the cutting wire. The cutting is carried out by means of the flowing of mortar, and the larger the mortar flow is, the faster the cutting speed is. The chip removal groove 3 can drive larger mortar flow under the mortar environment, and the mortar flow can reach three times of that of the traditional cutting wire. The method has the advantages that the conventional silicon carbide bar with the thickness of 150mm (6 inches) can be cut, the common carbon steel wire can be cut into one piece within 7 to 8 days, the spiral chip removal grooves 3 are used for removing chips, the cutting time is only half of the time, the yield and the speed are 100% higher than those of the conventional mode, the broken wires are few, the failure rate of equipment is low, the maintenance frequency is reduced, and the efficiency and the utilization rate of the equipment are higher.

When the diamond dust cutting wire works in a non-mortar environment, diamond dust particles with small volume can be arranged on the outer surface of the cutting wire, so that the friction on the surface of the cutting wire is increased, and the cutting effect is ensured.

In this embodiment, the single tungsten cutting filament 1 per cm has a twist angle of 3600 ° to 7200 °, that is, three tungsten cutting filaments 1 of one cm long are helically screwed to each other for 10 to 20 turns, and so on. The preferred helical twist angle of a single strand of tungsten cutting filament 1 per cm is 4800 deg. when the diameter of the single strand of tungsten cutting filament 1 is 0.02 mm. Here, the smaller the diameter is, the larger the helical twisting angle is, and when the diameter is larger and the helical twisting angle is smaller, a good twisting effect cannot be achieved; when the twisting angle is too large, not only is the winding diameter too large, but also the tensile strength is not greatly improved.

Example two:

referring to fig. 5 to 7, the structure and principle of the present embodiment are substantially the same as those of the first embodiment, except that the tungsten cutting filament 1 is provided in two strands, and the diameter of the integral cutting filament is twice as large as that of the single tungsten cutting filament 1 after being cut through the cutting hole. In this embodiment, the diameter of the single-strand tungsten filament 1 is preferably 0.05mm, so that the diameter of the overall filament is only 0.09mm, and the overall tensile strength and service life are better than those of a single-strand tungsten filament with a diameter of 0.09mm, and the cutting seam can be made thinner and the material can be saved.

In addition, the invention is not limited to tungsten wires, and can also be wires made of other metal materials and having certain tensile strength, and the twisted cutting wires can be formed by adopting the structure of the invention.

The above description is only a preferred embodiment of the present invention, and the technical solutions that achieve the objects of the present invention by basically the same means are all within the protection scope of the present invention.

Claims

1. The multi-strand combined rotary twisted cutting wire is characterized in that: the tungsten cutting wire comprises two or more tungsten cutting filaments (1), wherein the tungsten cutting filaments (1) are mutually spirally wound and twisted to form a cutting wire, and a plurality of annular pressing surfaces (2) are arranged on the outer surface of the cutting wire.

2. The multi-strand merged rotational twisted cutting wire of claim 1, wherein: the outer surface of the cutting wire is provided with a spiral chip removal groove (3) for cutting chips.

3. The multi-strand merged rotating twisted cutting wire according to claim 1 or 2, wherein: and diamond powder particles are arranged on the outer surface of the cutting wire.

4. Multi-strand merged rotating twisted cutting wire according to claim 1 or 2, characterized in that: the diameter of the single-strand tungsten cutting filament (1) is between 0.015mm and 0.15 mm.

5. Multi-strand merged rotating twisted cutting wire according to claim 1 or 2, characterized in that: the single-strand tungsten cutting filament (1) per cm has a helical twist angle of between 3600 ° and 7200 °.

6. The multi-strand merged rotating twisted cutting wire according to claim 1 or 2, wherein: the cross section of the cutting wire is circular.

7. The multi-strand merged rotating twisted cutting wire according to claim 1 or 2, wherein: the cross section of the cutting wire is a regular polygon.