JP6878191B2 - Capstan roll for wire drawing - Google Patents

Description

The present disclosure relates to capstan rolls.

A thin wire having a wire diameter of about 15 to 50 μm is used as a bonding wire for a semiconductor device (hereinafter, a bonding wire for a semiconductor device is simply referred to as a bonding wire) that electrically bonds an electrode on a semiconductor element and an external lead. ..

In order to obtain such a bonding wire, a wire drawing machine provided with a capstan roll is used. The wire drawing machine has a problem that when the capstan roll and the wire material slip, the wire material is scratched and the quality deteriorates. Further, if the surface roughness of the capstan roll is rough, there is a problem that the wire is broken. The applicant can suppress slippage between the capstan roll and the wire rod, and can suppress disconnection. The average length (Rsm) of the contour curve element of the sliding contact surface is 0.005 to 0.01 mm. The average is proposed (see Patent Document 1).

Conventionally, Au has been mainly used as the wire rod of the bonding wire, but the replacement with Cu is progressing mainly for LSI applications.

Japanese Unexamined Patent Publication No. 2009-178719

However, Cu is more easily oxidized than Au, and when trying to obtain a bonding wire made of Cu while suppressing slippage between the capstan roll and the wire, the surface is oxidized due to abrasion due to sliding contact with the capstan roll. There was a problem that it deteriorated and the wire was broken due to the deterioration.

An object of the present disclosure is to provide a capstan roll capable of suppressing slippage and reducing deterioration due to wear even when a bonding wire made of a wire rod such as Cu or Al, which is more easily oxidized than Au, is obtained. ..

Wire drawing capstan roll of the present disclosure will become diameter 15 to 50 m, a wire drawing capstan roll having a sliding contact surface with the wire of Cu or Al, from the contour line along the axial direction The required average length (RSm) of the sliding contact surface is 0.05 mm or more and 0.38 mm or less, and the arithmetic mean roughness (Ra) of the sliding contact surface is 0.002 μm or more and 0.035 μm or less.

According to the present disclosure, it is possible to provide a capstan roll for wire drawing that can reduce deterioration due to wear.

It is a perspective view which shows an example of the capstan roll for wire drawing processing of this embodiment. It is the schematic which shows an example of the wire drawing apparatus which is configured with the capstan roll for wire drawing processing shown in FIG.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. However, in all the drawings of the present specification, the same parts are designated by the same reference numerals and the description thereof will be omitted as appropriate as long as they do not cause confusion.

FIG. 1 is a perspective view showing an example of a capstan roll for wire drawing processing of the present embodiment (hereinafter, the capstan roll for wire drawing processing is simply referred to as a capstan roll).

The capstan roll 1 shown in FIG. 1 is a so-called cone type, and has a sliding contact surface 1a with a wire rod whose outer diameter gradually increases from reference numeral A attached to the shaft toward reference numeral B. .. Here, the capstan roll 1 may be integrally formed, or may be a one-stage member or a plurality of-stage members arranged adjacent to each other. The capstan roll 1 is rotatably installed around a rotation shaft 3 in a wire drawing device for stretching a wire rod such as Cu or Al, and rotates at, for example, 1000 rpm to 6000 rpm.

The capstan roll 1 has a length of, for example, about 200 mm to 225 mm, and has an outer diameter of about 30 mm to 160 mm, although the outer diameter varies depending on the position. Further, the insertion hole of the capstan roll 1 has a diameter of, for example, about 15 mm to 35 mm.

The capstan roll 1 of the present embodiment may be made of ceramics, and the main components are zirconium oxide, aluminum oxide, and silicon nitride from the viewpoint of less wear when the wire rods are repeatedly slidably contacted and a long life. Alternatively, it is preferably Sialon. Here, the main component is a component that accounts for 80% by mass or more of 100% by mass of all the components constituting the ceramics.

Ceramics containing zirconium oxide as a main component may contain, for example, silicon oxide and aluminum oxide as components other than the main components. Further, the ceramics containing aluminum oxide as a main component may contain, for example, silicon oxide, calcium oxide and magnesium oxide as components other than the main component. Ceramics containing silicon nitride or sialon as a main component may contain, for example, aluminum oxide and rare earth metal oxides as components other than the main components.

To confirm the main components of ceramics, first, the results obtained by measurement using an X-ray diffractometer (XRD) are collated with a JCPDS card to identify the contained compounds. Next, the content obtained by converting from the value obtained by measurement using a fluorescent X-ray analyzer (XRF) or an ICP (Inductively Coupled Plasma) emission spectrometer (ICP) into the specified compound. If is 80% by mass or more, it is the main component. Specifically, if it is confirmed from the measurement by XRD that ZrO ₂ is contained, and the value (content) obtained by converting the Zr value obtained by ICP into ZrO ₂ is 80% by mass or more, oxidation is performed. Zirconium is the main component of ceramics.

In the capstan roll 1 of the present disclosure, the average length (RSm) of the sliding contact surface 1a obtained from the contour line in the direction along the axial direction is 0.05 mm or more and 0.38 mm or less, and the arithmetic mean of the sliding contact surface 1a. The roughness (Ra) is 0.002 μm or more and 0.035 μm or less.

The average length (RSm) represents the average of the contour curve elements at the reference length, and only the reference length is extracted from the surface roughness curve in the direction of the average line, and a pair of adjacent peaks in this extraction portion. The sum of the horizontal direction of the valley is calculated, and the arithmetic mean value is expressed in millimeters.
The arithmetic mean roughness (Ra) represents the surface roughness.

In the capstan roll 1, when the average length (RSm) of the sliding contact surface 1a is 0.05 mm or more and the arithmetic average roughness (Ra) of the sliding contact surface 1a is 0.002 μm or more, the wire rod is a sliding contact surface. Since an appropriate frictional force is applied to the wire rod when it is in sliding contact with 1a, the slip of the wire rod on the sliding contact surface 1a can be reduced.

Assuming that the average length (RSm) of the sliding contact surface 1a is 0.38 mm or less and the arithmetic average roughness (Ra) of the sliding contact surface 1a is 0.035 μm or less, a certain amount of peaks are formed on the surface of the sliding contact surface 1a. Since the surface roughness of the sliding contact surface 1a can be made relatively small while providing the valley, it is possible to reduce the disconnection of the wire while suppressing the slip of the wire.

The average length (RSm) of the sliding contact surface 1a may be 0.06 mm or more in order to suppress slippage. Further, the average length (RSm) of the sliding contact surface 1a may be 0.28 mm or less in order to reduce the disconnection of the wire rod.

The arithmetic mean roughness (Ra) of the sliding contact surface 1a may be 0.007 μm or more in order to suppress slippage. Further, the arithmetic mean roughness (Ra) of the sliding contact surface 1a may be 0.026 μm or less in order to reduce the disconnection of the wire rod.

Further, the capstan roll 1 of the present embodiment may have a root mean square inclination (RΔq) of the sliding contact surface 1a of 0.004 or more and 0.015 or less.

The root mean square slope (RΔq) is an index indicating the local slope of the surface of interest. If the value is small, the surface has many flat parts, and if the value is large, the surface has many sloped parts. Shown.

When the root mean square inclination (RΔq) of the sliding contact surface 1a is 0.004 or more, a microscopic inclination on the sliding contact surface 1a can be secured, so that the slip of the wire rod on the sliding contact surface 1a can be further reduced. Can be done. When the root mean square inclination (RΔq) of the sliding contact surface 1a is 0.015 or less, it is possible to prevent the microscopic inclination of the sliding contact surface 1a from becoming too large, so that the disconnection of the wire can be further reduced. it can.

The squared average square root inclination (RΔq) of the sliding contact surface 1a may be 0.005 or more in order to suppress slippage of the wire rod. The root mean square inclination (RΔq) of the sliding contact surface 1a may be 0.011 or less in order to reduce the disconnection of the wire.

The average length (RSm), arithmetic average roughness (Ra), and root mean square slope (RΔq) of the sliding contact surface 1a are determined in accordance with JIS B 0601: 2001, and specifically, Co., Ltd. Using a surface roughness measuring machine (surf coder) SE500 manufactured by Kosaka Laboratory, the radius of the stylus may be 5 μm, the measuring length may be 2.5 mm, and the cutoff value may be 0.8 mm.

FIG. 2 is a schematic view showing an example of a wire drawing device 20 provided with the capstan roll 1 shown in FIG. First, the configuration and operation of the wire drawing device 20 shown in FIG. 2 will be described. The wire drawing device 20 has a so-called parallel hanging wire drawing structure. In the wire drawing device 20, the rotating shafts 3a and 3b are arranged at predetermined positions inside the machine base 11, and the capstan roll 1 is fixed to both of the rotating shafts 3a and 3b. That is, the capstan rolls 1 fixed to the respective rotation shafts 3a and 3b rotate in accordance with the rotation of the rotation shafts 3a and 3b. A plurality of dies (dice group) 12 are arranged in the gap between the rotating shaft 3a and the rotating shaft 3b. The capstan roll 1 is provided with a plurality of steps of outer peripheral surfaces whose outer diameter gradually increases from one end to the other.

Further, the wire drawing device 20 includes a drive motor 13, a drive pulley 14, a driven pulleys 15 and 16, a drive belt 17, and a driven belt 18 at the end of the machine base 11. A drive belt 17 is hung around the drive pulley 14 and the driven pulleys 15 and 16, the drive pulley 14 is rotated by the drive motor 13, and both the driven pulleys 15 and 16 are driven and rotated. The driven pulley 15 is connected to the rotary shaft 3b, the drive pulley 14 is connected to the rotary shaft 3a, and the drive motor 13 rotationally drives the rotary shafts 3a and 3b.

In the wire drawing device 20, the wire rod W sent from the outside via the guide roller (not shown) is conveyed while being hung around the two capstan rolls 1. Specifically, the wire rod W sent from the outside is passed through the die group 12 arranged between the capstan rolls 1, and the capstan roll 1 is rotated by driving the drive motor 13. At this time, the wire rod W is sequentially hung from the smaller outer diameter to the larger outer diameter (from the upper side to the lower side in the illustrated surface) among the multi-stage sliding contact surfaces of the capstan roll 1. .. The wire rod W is made of, for example, Cu. The wire W may be a metal wire other than Cu, such as Al.

In the wire drawing device 20, the capstan roll 1 is rotated by the drive of the drive motor 13, and the wire rod W is forcibly and sequentially passed through the die group 12 while being reduced in diameter and drawn. Although FIG. 3 shows an apparatus using two capstan rolls 1, the apparatus may be installed by further increasing the number of capstan rolls 1.

Next, a method for manufacturing the capstan roll of the present embodiment will be described.

In order to obtain a capstan roll made of ceramics containing zirconium oxide as a main component, a raw material is prepared using a zirconium oxide powder and each powder such as silicon oxide and aluminum oxide as a sintering aid. In addition to the sintering aid, yttrium oxide (Y ₂ O ₃ ), cerium oxide (CeO ₂ ), dysprosium oxide (Dy ₂ O ₃ ), magnesium oxide (MgO) and calcium oxide (CaO) are used as stabilizers. ) Etc., at least one of the powders may be added.

Then, using this raw material, it is molded at a molding pressure of 78 to 147 MPa by a molding method such as a cold hydrostatic molding method (CIP), cut into a desired shape, and then heated to 1350 to 1600 ° C. And bake.

In order to obtain a capstan roll made of ceramics containing aluminum oxide as a main component, a raw material is prepared using aluminum oxide powder and each powder such as silicon oxide, magnesium hydroxide and calcium carbonate as a sintering aid. To do. Then, this raw material may be molded by a molding method such as CIP at a molding pressure of 78 to 147 MPa, cut into a desired shape, and then fired at 1450 to 1700 ° C.

In order to obtain a capstan roll made of ceramics containing silicon nitride as a main component, first, a powder of metallic silicon and a powder of silicon nitride having a β conversion rate of 20% or less are prepared (metal silicon powder). / (Silicon nitride powder) is mixed so that the mass ratio is 1 or more and 10 or less to prepare the first powder. Further, as a sintering aid, a second powder obtained by weighing a magnesium aluminate powder and a metal compound powder is prepared. The metal compound is aluminum oxide, silicon dioxide, calcium carbonate, or the like. Further, instead of the magnesium aluminate powder, powders such as magnesium hydroxide, magnesium oxide and magnesium carbonate may be used. Then, a raw material is produced using a powder obtained by mixing the first powder and the second powder. Then, it may be molded at a molding pressure of 78 to 147 MPa by a molding method such as CIP, cut into a desired shape, and then fired at 1700 to 1860 ° C.

In order to obtain a capstan roll made of ceramics containing sialon as a main component, first, the β conversion rate is 40% or less, and the composition formula is represented by _{Si 6-Z} Al _Z O _Z N _8-Z. A raw material is prepared using a powder of silicon nitride having an amount z of 0.5 or less and powders of calcium oxide, aluminum oxide, and oxides of rare earth elements as sintering aids. Then, it may be molded at a molding pressure of 78 to 147 MPa by a molding method such as CIP, subjected to a cutting process for forming a recess in addition to a desired shape, and then fired at 1700 to 1800 ° C.

Then, the sliding contact surface is obtained by grinding the outer peripheral surface after firing, and then sliding the tape on which the abrasive grains are held by the resin to the outer peripheral surface for polishing. To obtain a sliding contact surface with an average length (RSm) of 0.05 mm or more and 0.38 mm or less and an arithmetic average roughness (Ra) of 0.02 μm or more and 0.035 μm or less, JIS R 6001 is used as an abrasive grain. -2: Using fine powder for precision polishing made of diamond having a particle size number of # 800 or more and # 1200 or less specified in 2017, the width of the tape is 1 mm or less, particularly 0. The traverse speed of the tape may be 120 mm / min or more so as to be 5 mm or less. Here, the traverse speed refers to the speed at which the tape is moved in the axial direction of the capstan roll while being slidably contacted with the outer peripheral surface.

Further, in order to obtain a sliding contact surface having a root mean square inclination (RΔq) of 0.004 or more and 0.015 or less, the traverse speed of the tape may be 500 mm / min or more.

Then, in order to fix the obtained capstan roll to the rotating shaft, the capstan roll may be inserted into the rotating shaft and fixed using a fastening member such as a screw.

The present disclosure is not limited to the above-described embodiment, and various changes, improvements, combinations, and the like can be made without departing from the gist of the present disclosure.

First, a zirconium oxide powder as a main component, each powder such as silicon oxide and aluminum oxide as a sintering aid, a yttrium oxide powder as a stabilizer, and a dispersant for dispersing the zirconium oxide powder. , The organic binder was wet-mixed with a ball mill to prepare a slurry.

Next, the slurry obtained by the above method is spray-granulated to obtain granules, and then the granules are molded by a cold hydrostatic pressure molding method (CIP) at a molding pressure of 98 MPa to form a columnar shape. I got a body.

Next, a through hole was formed in the axial direction using a drill made of sintered diamond.

Next, the molded product having the through holes formed was placed in a firing furnace and fired in an air atmosphere with a firing temperature of 1500 ° C. and a holding time of 5 hours to obtain a sintered body.

Then, after grinding the outer peripheral surface of the sintered body, the outer peripheral surface is polished with a tape in which abrasive grains are held by a resin to obtain a sample No. 1 to 11 were obtained. Here, as the abrasive grains, fine powder for precision polishing made of diamond whose particle size number specified in JIS R 6001-2: 2017 is shown in Table 1 was used. The polishing time and the difference between the width of the tape and the width of the outer peripheral surface are shown in Table 1 as ΔW, and the traverse speed of the tape was 120 mm / min.

In addition, sample No. In No. 12, the outer peripheral surface was left as it was ground, and this outer peripheral surface was used as a sliding contact surface.

In addition, the average length (RSm) and arithmetic mean roughness (Ra) of the sliding contact surface of each sample are determined by JIS B.
Obtained according to 0601: 2001, the measured values are shown in Table 1. The measurement was performed using a surface roughness measuring machine (surf coder) SE500 manufactured by Kosaka Laboratory Co., Ltd., and the measurement conditions were a stylus radius of 5 μm, a measurement length of 2.5 mm, and a cutoff value of 0. It was set to 0.8 mm.

Further, each sample was attached to a wire drawing device, and a wire rod made of Cu was drawn from a wire diameter of 0.025 mm to a wire diameter of 0.015 mm. The wire drawing speed was 100 m / min for all the samples. For each sample, the presence or absence of slippage and disconnection of the wire rod until the wire was drawn 1000 m was confirmed, and the results are shown in Table 1.

A sample in which no slip occurred in the slip column of Table 1 indicates that no slip occurred, and a sample in which yes was entered indicates that slip occurred.

Further, the sample in which no disconnection is entered in the disconnection column of Table 1 indicates that the disconnection did not occur, and the sample in which the disconnection is entered indicates that the disconnection occurred.

As shown in Table 1, the average length (RSm) of the sliding contact surface is 0.05 mm or more and 0.38 mm or less, and the arithmetic average roughness (Ra) of the sliding contact surface is 0.002 μm or more and 0.035 μm or less. A sample No. No slips and disconnections occur in 2, 4 to 6, 8 to 10, and the wires are satisfactorily stretched.

After grinding the outer peripheral surface of the sintered body produced in Example 1, the outer peripheral surface of the sample No. was polished with a tape in which abrasive grains were held by a resin. 13-18 were obtained. Here, as the abrasive grains, fine powder for precision polishing made of diamond having a particle size number of # 1000 defined in JIS R 6001-2: 2017 was used. The difference between the width of the tape and the width of the outer peripheral surface was 0.5 mm, the polishing time was 60 seconds, and the traverse speed of the tape was as shown in Table 2.

In addition, the average length (RSm) and arithmetic mean roughness (Ra) of the sliding contact surface of each sample are determined by JIS B.
As a result of obtaining according to 0601: 2001, the average length (RSm) of each sample was 0.17 to 0.18 mm, and the arithmetic mean roughness (Ra) was 0.021 to 0.022 μm. there were. Table 2 shows the measured values of the root mean square slope (RΔq) of the sliding contact surface. For the measurement, a surface roughness measuring machine (surf coder) SE500 manufactured by Kosaka Laboratory Co., Ltd. was used, and the measurement conditions were a stylus radius of 5 μm, a measurement length of 2.5 mm, and a cutoff value. It was set to 0.8 mm.

Further, each sample was attached to a wire drawing device, and a wire rod made of Cu was drawn from a wire diameter of 0.025 mm to a wire diameter of 0.015 mm. The wire drawing speed was 100 m / min for all the samples. For each sample, the presence or absence of slippage and disconnection of the wire rod until the wire was drawn 2000 m was confirmed, and the results are shown in Table 2. The length of the wire rod is twice the length of the wire rod produced in Example 1.

A sample in which no slip occurred in the slip column of Table 2 indicates that no slip occurred, and a sample in which yes was entered indicates that slip occurred.

Further, the sample in which no disconnection is entered in the disconnection column of Table 2 indicates that the disconnection did not occur, and the sample in which the disconnection is entered indicates that the disconnection occurred.

As shown in Table 2, the sample No. Sample Nos. 14 to 17 are outside this range because the root mean square inclination (RΔq) of the sliding contact surface is 0.004 or more and 0.015 or less. It can be seen that slip and disconnection are less likely to occur than 13 and 18.

1 Capstan roll 1a Sliding contact surface 3 Rotating shaft 11 Machine base 12 Dice 13 Drive motor 14 Drive pulley 15, 16 Driven pulley 17 Drive belt 18 Driven belt 20 Wire drawing device

Claims (2)

A capstan roll for wire drawing having a sliding contact surface with a Cu or Al wire having a wire diameter of 15 to 50 μm, and the average length of the sliding contact surface obtained from a contour line along the axial direction ( RSm) is at 0.05mm or more 0.38mm or less, the arithmetic average roughness of the sliding surface (Ra) is less than 0.035μm than 0.002 .mu.m, the capstan roll drawing. The capstan roll for wire drawing according to claim 1, wherein the root mean square inclination (RΔq) of the sliding contact surface is 0.004 or more and 0.015 or less.

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