JP3990234B2 - Saw wire manufacturing equipment - Google Patents

Description

[0001]
[Industrial application fields]
The present invention relates to a saw wire manufacturing apparatus used for cutting expensive materials such as silicon crystals, artificial crystals, cemented carbides, ceramics and the like, which are base materials for semiconductor wafers. Thus, the production cost can be reduced.
[0002]
[Prior art]
In recent years, fixed-abrasive 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 metal wire is drawn to reduce the diameter, and a resin bond (thermosetting resin) is laminated thereon, and the resin bond layer densely adheres to the surface. There are those in which hard fine pieces (hereinafter referred to as abrasive grains) such as diamond abrasive grains, CBN abrasive grains and hard fine fibers are fixed, or those in which abrasive grains are embedded and fixed in a plating layer by composite plating. The former method of manufacturing a fixed abrasive saw wire is a method in which a steel wire is passed through a resin bond mixed with abrasive grains to attach the resin bond mixed with abrasive grains to the surface, and this is cooled and hardened. There is a method for producing the latter fixed abrasive type saw wire, in which the abrasive particles are suspended in a plating solution (Ni plating solution, etc.) and the abrasive particles adhere (deposit) to the plating layer during plating (electroplating). It is a method to make.
[0003]
In the latter case, the adhesive force of the abrasive grains to the metal wire surface is sufficient, and thus the cutting performance is maintained for a long time, but the abrasive particles suspended in the plating solution are fixed and held with sufficient adhesive force. Therefore, the plating layer must be formed to the required thickness, and the thickness of the plating layer must be as uniform as possible in order to make the adhesive strength of the abrasive grains constant. It is.
The composite plating on the wire is performed with an apparatus as shown in FIG. 1. The wire is run in a plating solution mixed with abrasive grains, and the wire is plated by feeding with a power feeding roller. Abrasive grains are attached.
Since the feed roller is required to have corrosion resistance, stainless steel is generally used. Power is supplied to the wire by direct contact between the power supply roller and the wire, but since non-conductive abrasive particles are attached to the surface of the power supply roller, the metal surface of the wire and the metal surface of the power supply roller Are not always in stable contact, and therefore, the electrical resistance between the wire and the feed roller always fluctuates. Further, the above-mentioned tendency is particularly remarkable because the wire on which the plated layer mixed with the abrasive grains is in contact with the power feeding roller on the downstream side.
[0004]
On the other hand, a direct current is used for electroplating, and this direct current rectifies the current from an alternating current power source with a rectifier, and controls this at a constant current value, so that the formation speed of the plating layer (the formed plating layer) (Thickness) is controlled to be constant. However, although the DC power supply is controlled by a constant current, as described above, the electrical resistance between the wire and the feeding roller constantly fluctuates, so the voltage fluctuates severely, and if the voltage exceeds a predetermined limit, the current value As a result, the thickness of the plating layer (the thickness of the deposited layer) is not constant, which causes a poor quality of the saw wire. In order to prevent this, it is necessary to prevent the voltage rise from exceeding a predetermined limit by suppressing the fluctuation of the electric resistance as much as possible.
[0005]
[Problems to be solved by the invention]
In view of this, the present invention ensures the necessary electrical conductivity between the power supply roller and the wire even when the abrasive particles are attached to the power supply roller and the abrasive particles are attached to the wire. The problem is to devise the power supply roller so that the voltage rise does not exceed a predetermined limit.
[0006]
[Means for Solving the Problems]
The means taken in order to solve the above problems is that, in a saw wire manufacturing apparatus using composite plating , the outer peripheral surface of the power supply roller is covered with a conductive fiber web on which countless fine fibers protrude. is there.
[0007]
[Action]
Innumerable fine fibers protrude from the surface of the conductive fiber web (nonwoven fabric). Therefore, when a wire is wound around the fiber web, the protruding fine fibers (protrusions) always come into contact with the surface of the plated layer of the wire even if abrasive grains are attached to the fiber web, and between the feeding roller and the wire. The required continuity is always ensured by the protrusions. The same applies to the case where abrasive grains are attached to the wire.
[0008]
Embodiment 1
Embodiment 1 is that the fiber web in the solution means is made of stainless steel, copper fiber or chemical fiber containing or braided conductive metal fiber. However, the fiber web is preferably a material that is corrosion resistant and has excellent wear resistance.
Embodiment 2
Embodiment 2 is that the fiber web in the solution means is made of metal fibers having a wire diameter of 5 to 20 μm.
Embodiment 3
Embodiment 3 is that the power supply roller is made of stainless steel, copper, aluminum, ceramic or plastic, or other material having excellent corrosion resistance.
Embodiment 4
In the fourth embodiment, the power feeding roller has an annular groove on the outer periphery, and the annular groove is covered with the metal fiber web.
[0009]
【Example】
The power supply roller 10 of this embodiment is made of stainless steel having an excellent corrosion resistance and has a diameter of 80 mm and a width of 20 mm, and an annular groove (groove width of 10 mm, depth of 5 mm) having an arcuate cross section is formed on the outer periphery thereof.
A web 11 having a thickness of 5 mm made of stainless fiber (fiber thickness is 12 μm, but can be 5 to 20 μm) is wound around the annular groove and bonded with an adhesive (conductive tape).
A wire is wound around the power supply roller having the above-described structure to run.
A piano wire having a wire diameter of 0.2 mm is run in a Ni plating solution in which diamond abrasive grains having a particle size of 30 to 40 μm are suspended. This is the feed current 1A at this time.
As the wire travels, the voltage fluctuates in the range of 2.5 to 4.0 V, but the current value during this period is maintained at 1 A, the adhesion of the plating and abrasive grains is almost uniform, and there is no deterioration in the quality. Absent. On the other hand, in the conventional example in which the outer peripheral surface is not covered with the conductive fiber web 11, the voltage fluctuates in the range of 3.0 to 15.0 V under the same conditions, and the adhesion of plating and abrasive grains Was non-uniform and significant quality degradation was observed.
[0010]
Since the outer peripheral surface of the power supply roller body has conductivity, it is not always necessary to have conductivity, and other excellent corrosion resistance materials such as ceramic and plastic can be used. When the power supply roller main body is non-conductive, a small-diameter power supply roller may be brought into contact with the outer periphery of the power supply roller so that the power supply roller and the coating layer made of the fiber web are made conductive.
Moreover, about the fiber of an electroconductive web, it is excellent in corrosion resistance, such as a copper fiber, What is necessary is just high conductivity.
The annular groove on the outer periphery of the power supply roller may be U-shaped or V-shaped in cross section, and does not necessarily have to have an annular groove. When there is no annular groove, a guide roller for the wire may be provided adjacent to the upstream side of the power supply roller, and the guide roller may guide the wire so that it does not come off the power supply roller.
In addition, by forming the annular groove on the outer periphery of the power supply roller as described above, the fiber web wound around and attached to the groove is less likely to come off during the rotation of the roller.
[0011]
【The invention's effect】
As described above, according to the present invention, it is possible to stabilize the power supply for composite plating in the saw wire manufacturing apparatus, and therefore, it is possible to make the plating layer and the abrasive grain adhesion uniform. Quality degradation can be reliably prevented.
[Brief description of the drawings]
FIG. 1 is an overall view of an apparatus for manufacturing a saw wire by composite plating.
FIG. 2 is a side view of the power supply roller according to the embodiment.
FIG. 3 is a front view schematically showing a contact state between a wire and a power feeding roller in a conventional technique.
FIG. 4 is a front view schematically showing a contact state between a wire and a feeding roller in the embodiment.
[Explanation of symbols]
10: Feed roller 11: Conductive fiber web

Claims (5)

In a saw wire manufacturing apparatus using composite plating, a saw wire manufacturing apparatus in which an outer peripheral surface of a power supply roller is covered with a conductive fiber web on which countless fine fibers protrude . 2. The saw wire manufacturing apparatus according to claim 1, wherein the fiber web is made of stainless fiber or copper fiber. 3. The saw wire manufacturing apparatus according to claim 1, wherein the fiber web is made of a metal fiber having a wire diameter of 5 to 20 [mu] m. 4. The saw wire manufacturing apparatus according to claim 1, wherein the power supply roller is made of stainless steel, copper, ceramic or plastic. 5. The saw wire manufacturing apparatus according to claim 1, wherein the feed roller has an annular groove on the outer periphery, and the annular groove is covered with the metal fiber web.

Images