JP2004058169A - Saw wire manufacturing method and saw wire - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To devise a manufacturing method for improving the productivity by firmly fixing abrasive grains by a mechanical method and improving the linear velocity of a wire in a manufacturing process. <P>SOLUTION: A metal wire is coated with a prescribed thickness of copper, zinc, nickel, aluminium, or brass, the coated metal wire (w) is laid in contact with feed members 4 and 4 disposed at a prescribed interval, the coated layer of the metal wire is heated by resistance to be softened, the metal wire whose coated layer is heated and softened is fed with the abrasive grains D before passing through a pair of annular grooved rollers 2 and 2, the abrasive grains stuck to the softened coated surface are pressurized and pushed in the softened coated layer by the annular grooved rollers, and the coated layer is cooled and hardened so as to fix the abrasive grains to the coated layer. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
[Industrial applications]
The present invention relates to a method of manufacturing a saw wire used for cutting expensive materials such as silicon crystal, which is a base material of a semiconductor wafer, artificial quartz, cemented carbide, and ceramics, and improves the productivity. As a result, the production cost can be reduced.
[0002]
[Prior art]
In recent years, fixed abrasive type saw wires in which fine abrasive grains such as diamond are fixed to the surface of a thin metal wire have begun to be used. In this conventional fixed-abrasive saw wire, for example, a resin wire (thermosetting resin) is laminated on a metal wire whose diameter has been reduced by wire drawing, and the surface of the resin wire is densely diamond-bonded by the resin bond layer. Hard particles (hereinafter referred to as abrasive particles) such as particles, CBN abrasive particles, and hard fine fibers are fixed, or abrasive particles are fixed by embedding the abrasive particles in a plating layer. The former method of manufacturing a fixed abrasive type saw wire is a method in which a resin bond mixed with abrasive grains is attached to the surface by passing the wire through a resin bond mixed with abrasive grains, and this is cooled and hardened. The latter method of manufacturing a fixed abrasive type saw wire is a method in which abrasive grains are suspended in a plating solution so that the abrasive grains adhere to a plating layer during plating (electroplating). Note that the above “CBN” is an abbreviation for cubic boron nitride.
[0003]
In the former case, if the distribution of the mixed abrasive grains in the resin bond is non-uniform, and in the latter case, if the distribution of the abrasive grains in the plating solution is non-uniform, the distribution of the abrasive grains adhered to the saw wire surface is reduced. In the former case, the abrasive grains fall off during use and their distribution becomes coarse because the adhesive strength of the abrasive grains to the metal wire surface is not always sufficient, resulting in poor saw wire cutting performance. There is a problem of lowering.
[0004]
In the latter case, the bonding strength of the abrasive grains to the metal wire surface is sufficient, and therefore, the cutting performance is maintained for a long time. However, it is necessary to fix and hold the abrasive grains with a sufficient bonding force. A plating layer must be formed to a thickness. In this plating process, a thin metal wire is passed through the plating solution at a very low speed, and the plating layer is grown to a required thickness during the plating process. In addition, there is a problem that the wire speed of the wire for plating is low, so that the productivity of the saw wire is low and the production cost is high.
[0005]
[Problems to be solved by the invention]
The present invention is fundamentally different from any of the conventional saw wire manufacturing methods, and has a new manufacturing method capable of improving the productivity by increasing the wire speed of the wire rod in the manufacturing process with a high bonding force to the abrasive grains and increasing the wire speed in the manufacturing process. The idea is to devise it.
[0006]
[Means for Solving the Problems]
The manufacturing method for solving the above-mentioned problem is constituted by the following (a) to (e).
(A) Metal wire is coated with copper, zinc, nickel, aluminum or brass of required thickness,
(B) A metal wire coated with copper, zinc, nickel, aluminum or brass is run while being in contact with a power supply member arranged at a predetermined interval, and the coating layer of the metal wire is softened by resistance heating,
(C) supplying abrasive grains to the metal wire whose coating layer has been heated and softened before passing through the abrasive grain pressing means;
(D) pressing the abrasive grains adhered to the softened coating surface into the softened coating layer by applying pressure by the abrasive grain pressing means;
(E) cooling and curing the coating layer to fix the abrasive grains to the coating layer;
[0007]
[Action]
In a state where the coating layer obtained in the step (b) is heated and softened in the step (b), the abrasive grains are softened by passing through the abrasive grain pressing means together with the abrasive grains adhered in the step (c). Pressed into the coating layer. Since the softened coating layer contracts when cooled and hardened, the abrasive grains are extremely firmly fixed while being pressed into the coating layer.
The copper, zinc, nickel, aluminum or brass coating layer of the metal wire is heated and softened instantaneously while passing between the power supply members, and the abrasive grains are softened and coated when passing through the abrasive pressing means. The abrasive grains are pressed into the layer and the abrasive grains are fixed by cooling and hardening of the coating layer.
Since the steps (b) to (d) are instantaneous, it is possible to increase the linear velocity of the traveling metal wire.
[0008]
Embodiment 1
In the first embodiment, as a solution means (means for solving the above-mentioned problem), the abrasive grain pressing means is a pair of annular grooved rollers (free rollers), and the abrasive grains are formed by the pair of annular grooved rollers. Pressing and pressing into the softening coating layer.
[Action]
Since the abrasive particles attached to the softening coating layer of the metal wire pass through the circular hole between the pair of pressure rollers formed by the annular groove, the height of the tip of the abrasive particles protruding from the surface of the metal wire from the coating layer is increased. Is provided by the circular hole.
[0009]
Embodiment 2
In a second embodiment, a solution is to pass the pair of pressure rollers and then pass the forming die.
[Action]
The outer diameter of the saw wire is adjusted to the inner diameter of the die by passing the coating layer through the forming die while the abrasive layer is pressed into the coating layer in a softened state.
[0010]
Embodiment 3
Embodiment 3 is that the coating of requirement (A) of the solution is a plating layer.
The plating can be electroplating or hot-dip plating.
[0011]
Embodiment 4
Embodiment 4 is that the thickness of the coating layer in the solving means is ２〜 to ／ of the average diameter of the abrasive grains.
[Action]
The depth at which the abrasive grains are embedded in the coating layer is substantially equal to the thickness of the coating layer. If the burying depth is 1/2 or more of the abrasive grain size, the holding force of the coating layer against the abrasive grains is stably secured. If the burying depth does not significantly exceed 2/3 of the abrasive grain size, The protrusion height of the grains from the surface of the coating layer is sufficiently ensured, and therefore, high cutting performance of the saw wire is ensured.
[0012]
【Example】
Next, embodiments will be described with reference to the drawings.
The specifications of the saw wire vary depending on the purpose of use, such as a wire diameter of 0.02 to 0.50 mm and an average grain size of abrasive grains of 5 to 300 μm. In this embodiment, the SUS304 wire of 0.20 mm is used. Is coated with a copper (Cu) plating layer having a thickness of 20 μm, and CBN abrasive grains having an average particle diameter of 30 μm are fixed thereto.
The manufacturing apparatus has a vertically arranged hopper 1 for supplying CBN abrasive grains, a roller 2 having an annular groove for pressurization, and a die 3.
Power supply brushes 4 and 4 are provided on the upstream side of the hopper 1 and on the downstream side of the grooved roller 2, and a 0.20 mm SUS wire (hereinafter referred to as a SUS wire or a wire) w covered with a copper plating layer is provided on the upstream side. It passes through the power supply brush 4, the hopper 1, the roller 2 with the annular groove for pressurization, the power supply brush 4 on the downstream side, and the die 3 in order, and travels from top to bottom.
The material of the wire in the above embodiment is SUS304, but is not limited thereto, and a carbon steel wire such as a hard steel wire or a piano wire can also be used.
[0013]
In addition, since it is desirable to make the time during which the SUS wire w is heated for feeding as long as possible, in this example, the feeding brush is connected to the upstream side of the hopper 1 and the groove so that the interval between the feeding brushes 4 and 4 becomes long. It is arranged downstream of the attaching roller 2.
Although the power supply brush 4 on the downstream side contacts the wire surface on which the non-conductive CBN abrasive grains protrude, the projecting height of the CBN abrasive grains from the wire surface is 10 μm on average. (Copper plating layer). Therefore, power supply from the power supply brush 4 on the downstream side to the wire w is performed without any trouble.
[0014]
By the way, when the wire w passes between the rollers (free rollers) 2, 2, the abrasive grains D are pressed by the rollers 2, 2 to be smoothly pushed into the plating layer c, and the surface of the pushed abrasive grains is plated. It is necessary that the coating c is familiar and adheres. For that purpose, the plating coating needs to be softened. On the other hand, the thickness of the plating layer c must be kept as uniform as possible, and the shape retention must be ensured. Therefore, the heating temperature must be a temperature at which the plating layer c does not flow. There is. From the above, the heating temperature is preferably in the range of 200 to 800 ° C. for copper and 200 to 500 ° C. for zinc.
[0015]
The outer circumference of the roller 2 has an annular groove 2g having a semicircular cross section, and the radius of the annular groove is 130 μm, which is 10 μm larger than the radius 120 μm (wire radius 100 μm + plating thickness 20 μm) of the coating layer of the wire w. Since the average particle diameter of the CBN abrasive grains is 30 μm, when the abrasive grains D pass between the rollers 2, 2/3 of the abrasive grains D are buried in the plating layer c, and the abrasive grains D project from the plating layer c by about 10 μm. (See FIG. 3).
After passing through the rollers 2 and 2, the wire w passes through a die 3 having a cross-sectional shape shown in FIG. 4.
When passing through the rollers 2, 2, the outer shape of the plating layer c is distorted, and therefore, the outer shape of the virtual circle S at the tip of the abrasive grain is not a perfect circle. After cooling, the copper plating layer c shrinks and hardens, and the abrasive grains D are firmly fixed to the copper plating layer c to form the saw wire W.
[0016]
【The invention's effect】
As described above, the present invention is manufactured by an appropriate method, copper, zinc, nickel, aluminum, a metal wire coated with a plating layer of brass is resistance-heated to soften the plating layer, and abrasive grains are attached thereto. Attaching the abrasive grains to the plating layer by pressurizing the adhered abrasive grains with a pressurizing means, and fixing the abrasive grains to the plating layer by using the adhesive force caused by cooling, heat shrinkage, and hardening of the plating layer. , The saw wire manufacturing method is simplified, and the productivity can be improved by increasing the linear speed in the saw wire manufacturing process, so that the saw wire manufacturing cost can be reduced. it can.
Further, in the saw wire according to the manufacturing method of the present invention, since the abrasive grains are fixed and held in a state of biting into the hardened plating layer, the holding force against the abrasive grains is strong, and the abrasive grains do not fall off, and are excellent for a long time. Cutting performance is maintained.
Also, since the metal wire is energized and heated directly by resistance, the plating layer is softened, and the abrasive grains are pressed into the metal layer, causing the production equipment to be extremely simple. It is.
Since the linear velocity of the metal wire can be significantly increased as compared with the case where the abrasive grains are fixed by resin or plating, the productivity is extremely high.
[Brief description of the drawings]
FIG. 1 is a schematic diagram of an embodiment.
FIG. 2 is a side view of an annular grooved roller.
FIG. 3 is a cross-sectional view of a saw wire manufactured in an example.
FIG. 4 is a sectional view of a die.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... CBN abrasive hopper 2 ... Roller with an annular groove 2g ... Annular groove 3 ... Die 4 ... Power supply brush D ... Diamond or CBN abrasive (abrasive)
w ... SUS wire covered with copper plating layer (SUS wire or wire)
c: Copper plating layer (plating layer or plating coating)
W: Saw wire

Claims (6)

Cover metal wire with required thickness of copper, zinc, nickel, aluminum or brass,
A metal wire coated with copper, zinc, nickel, aluminum or brass is run while being in contact with a power supply member arranged at a predetermined interval, and the coating layer of the metal wire is softened by resistance heating,
The coating layer is supplied with abrasive grains before passing through the abrasive grain pressure bonding means to the heat-softened metal wire,
The abrasive grains adhered to the softening coating surface are pressed into the softening coating layer by applying pressure by the abrasive pressing means,
A saw wire manufacturing method in which the coating layer is cooled and hardened to fix the abrasive grains to the coating layer. 2. The saw wire manufacturing method according to claim 1, wherein after passing through said abrasive grain pressing means, the forming die is continuously passed through. 2. The saw wire manufacturing method according to claim 1, wherein said abrasive grain pressing means is a pair of annular grooved rollers. 2. The saw wire manufacturing method according to claim 1, wherein the abrasive grains are diamond or CBN. The method according to claim 1, wherein the coating of copper, zinc, nickel, aluminum or brass is a plating layer. The saw wire manufactured by the saw wire manufacturing method according to claim 1, wherein 1/2 to 2/3 of the average abrasive grain size is embedded in the coating layer.

Images