JP2006342375A - Method for manufacturing extra-fine polishing wire - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To stably supply an extra-fine polishing wire which has few deflections, superior handleability and superior straightness, and in which the deflections hardly change their shapes before and after an etching step. <P>SOLUTION: The method for manufacturing the extra-fine polishing wire comprises the steps of: heat-treating a piano wire; drawing it; gradually reducing a diameter of the wire finally into a required diameter (0.010 to 0.050 mm); and annealing the final-drawn wire at a low temperature of 300 to 500°C in an inertgas atmosphere, while applying such a level of tension as to keep it straight to the wire. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a method for producing an ultrafine polishing wire having a wire diameter of 0.010 to 0.050 mm, particularly an ultrafine polishing wire that is used by tapering a tip portion by etching.

  Wires (polishing lines) used to polish the inner wall of a narrow hole include a relatively thick one and a thin one. Further, for example, a wire used for polishing the inner wall of a capillary at the tip of a bonding wire used in a semiconductor device is a very fine polishing wire made of a piano wire having a wire diameter of 0.010 to 0.050 mm.

  In these polishing wires, a piano wire is usually drawn after heat treatment, and the final wire is drawn to have a required wire diameter. In the case of an ultra fine ground wire, the wire finished by the final wire drawing (wire drawn up wire) is used as it is, and when used, taper processing is performed by etching over a length of about 40 to 60 cm from the tip, and a long taper , Insert this into the hole to be polished from the tip, apply diamond abrasive grains kneaded with oil, gradually polish the inner wall of the hole with the taper part, and finish with the straight part at the end Use it.

  The ultra-fine polishing wire is used in this way, but because it is thin itself, it does not have a waist, and it is easy to have a characteristic small wire peculiar to the ultra-fine drawn wire, and it originally shows straightness. It is difficult to handle, and the handling characteristics are poor due to the small line habit.

  In addition, as described above, the ultrafine polishing wire is tapered by etching over a length of about 40 to 60 cm from the tip during use. As a result, the residual stress between the wire surface layer and the inner layer is reduced. When the balance is lost, the line habit changes and the straightness may be further deteriorated.

  Therefore, if the drawn wire is used as an ultrafine polishing wire as it is, it is difficult to stably supply a wire with high straightness, and those with poor straightness are not easy to pass through a narrow hole. It is difficult to perform stable polishing. Therefore, only those with good straightness must be selected and used in lot units.

  Therefore, a wire used as an ultrafine polishing wire is required to improve straightness by performing some kind of processing after the drawing process, not the drawn wire as-is.

However, methods commonly known as methods for improving the straightness of the wire include a method of producing straightness by repeatedly applying alternating strain with a straightening roller, and a residual stress (internal stress) by annealing (tension-added annealing). (For example, refer to Patent Document 1). Among these methods, the straightness with a straightening roller is an ultrafine wire having a wire diameter of 0.010 to 0.050 mm. In this case, since the wire diameter is too small, there are problems such as disconnection and adjustment difficulty, and it is difficult to carry out itself, and even if it is carried out, residual stress due to alternating strain occurs, and etching during use Accordingly, the balance of the residual stress may be lost, and the straightness may be deteriorated. In addition, the method of obtaining straightness by annealing cannot avoid a significant decrease in strength of the wire. Under such circumstances, it is usual to employ a wire that has been drawn as it is for an ultrafine polishing wire having a wire diameter of 0.010 to 0.050 mm.
JP-A-9-141370

  As described above, the ultrafine polishing wire having a wire diameter of 0.010 to 0.050 mm is thin and has no waist as it is a drawn wire, and is easily prone to small wire habits. Therefore, it is difficult to stably supply a wire with high straightness because there is a possibility that the line habit will change due to the etching and the straightness may deteriorate. Moreover, even if it tries to give straightness by the conventional method, the method of giving straightness by the straightening roller is difficult to carry out because the wire diameter is too small. There is a risk of further deterioration, and the method of producing straightness by annealing cannot avoid a significant decrease in strength of the wire.

  However, it is possible to stably supply an ultra-fine polishing wire that is excellent in straightness with almost straight shape, with few wire habits and excellent handleability, and almost no change in wire habits before and after etching. It is a request that we want to achieve by all means and is a problem to be solved.

  This invention solves the said subject by carrying out the low temperature annealing process of the wire after final wire drawing at the temperature of 300-500 degreeC.

  That is, this invention is a manufacturing method of the wire for ultra-fine grinding | polishing with a wire diameter of 0.010-0.050mm which uses a piano wire as a raw material, Comprising: The wire material (drawn up wire) after the final wire drawing processing is 300-500. A low temperature annealing treatment is performed at a temperature of ° C.

  The wire that has been drawn is subjected to a low-temperature annealing treatment at a temperature of 300 to 500 ° C., so that the residual stress is reduced, the wire habit is almost eliminated, and the wire has a substantially straight straightness. And since this wire has reduced residual stress and almost no line habit, the change of the line habit when etched is small, and the straightness hardly changes.

  Therefore, according to the above manufacturing method, there is little wire habit and excellent handleability, and the wire for ultra-fine polishing that is almost straight and excellent in straightness with almost no change in wire habit before and after etching can be stably supplied. Can do.

  This manufacturing method can be applied to the ultrafine wire having a wire diameter of 0.010 to 0.050 mm without any trouble. And since it heat-processes at the temperature below a transformation point, there is little intensity | strength fall. When the low temperature annealing treatment is performed at a temperature of 300 to 500 ° C., the decrease in tensile strength is relatively small, and it can be used. In particular, when the processing temperature is 300 to 400 ° C., the decrease in tensile strength can be suppressed to around 10%.

  Here, the low-temperature annealing treatment is preferably performed by applying tension in an inert gas atmosphere. If the wire surface is oxidized by the low-temperature annealing treatment, etching cannot be performed due to the oxide scale. Such problems can be solved by performing a low-temperature annealing treatment in an inert gas atmosphere. The low-temperature annealing treatment is preferably performed in a state where a certain amount of tension is applied to the wire. By doing so, it becomes easy to obtain an ultrafine polishing wire having a substantially straight shape and a small residual stress.

  As is clear from the above description, according to the present invention, there are few line habits and excellent handleability, and the line habits hardly change before and after the etching for taper processing in use. It is possible to stably supply an ultrafine polishing wire having a required tensile strength and a wire diameter of 0.010 to 0.050 mm, which has excellent properties.

  In particular, by performing the low-temperature annealing treatment in an inert gas atmosphere, it is possible to prevent the wire surface from being oxidized so that etching can be performed without any trouble, and the wire is subjected to low temperature with a certain amount of tension applied thereto. By performing the annealing treatment, it becomes easy to obtain an ultrafine polishing wire having a substantially straight shape and a small residual stress.

  As an embodiment of the present invention, for example, a method of manufacturing an ultrafine polishing wire having a wire diameter of 0.010 to 0.050 mm made of piano wire for polishing an inner wall of a capillary at the tip of a bonding wire used in a semiconductor device, for example. An example will be described.

  In use, the ultrafine polishing wire of this embodiment is tapered by etching over a length of about 40 to 60 cm from the front end to form a long taper, and this is inserted into a hole to be polished from the front end. It is used in such a way that an abrasive kneaded with oil is applied, the inner wall of the hole is gradually polished at the taper part, and finally the straight part is finished.

  Etching is carried out by hanging the wire vertically and gradually immersing it in nitric acid from the tip to a length of about 40 to 60 cm, and then gradually pulling it up, and adjusting the dipping and pulling speeds at that time. As a result, a necessary taper is attached to the tip of the wire.

  In this embodiment, a piano wire is used as the material for the ultrafine polishing wire. Then, the piano wire is drawn after the heat treatment, and the wire diameter is gradually reduced to obtain a wire having a required wire diameter (0.010 to 0.050 mm) by final drawing.

  And the tension | tensile_strength which hold | maintains a straight shape is added to the wire after the final wire-drawing process in inert gas atmosphere, and low temperature annealing processing is performed at the temperature of 300-500 degreeC.

  The ultrafine polishing wire produced in this way is subjected to a low-temperature annealing treatment at a temperature of 300 to 500 ° C., so that the residual stress is reduced, the wire habit is almost eliminated, and the wire has a substantially straight straightness. And since this wire has reduced residual stress and almost no line habit, the change of the line habit when etched is small, and the straightness hardly changes.

  In this way, it is possible to stably supply an ultra-fine polishing wire that is excellent in straightness and has almost straight shape with little wire habit and excellent handleability and almost no change in wire habit before and after etching.

  And the fall of the tensile strength when carrying out the low temperature annealing process at the temperature of 300-500 degreeC is comparatively small, and it can be used. In particular, when the processing temperature is 300 to 400 ° C., the decrease in tensile strength can be suppressed to around 10%.

  Further, by performing the low-temperature annealing treatment in an inert gas atmosphere, the wire surface is prevented from being oxidized and can be etched without any trouble.

  The example of the ultrafine polishing wire for polishing the inner wall of the capillary at the tip of the bonding wire used in the semiconductor device has been described above. However, the present invention is not limited to the various ultrafine polishing for different uses having a wire diameter of 0.010 to 0.050 mm. It can be applied to a manufacturing method for wire.

  In the following table (Table 1), as an example of the present invention, a wire having a wire diameter of 0.020 mm, which was drawn after heat treatment of a piano wire, was added with a tension to maintain a straight shape in an inert gas atmosphere, For the three types of wires (Examples 1 to 3) obtained by heat treatment (low temperature annealing treatment) at different treatment temperatures and treatment speeds, the results of measuring the tensile strength and wire habit were similarly drawn after heat treatment of the piano wire. A wire drawn up wire (original wire) with a wire diameter of 0.020 mm, a wire processed with a correction roller by a conventional method (“roller correction”), and a wire annealed by a conventional method (“annealing”), It shows with the measurement result of the wire ("Comparative example 1") heat-processed at the temperature lower than this invention, and the wire ("Comparative example 2") heat-processed at a temperature higher than this invention.

  “Example 1” has a processing temperature of 320 ° C. and a processing speed of 10 m / min, “Example 2” has a processing temperature of 400 ° C. and a processing speed of 50 m / min, and “Example 3” The temperature is 480 ° C. and the processing speed is 200 m / min. “Roller correction” has a processing speed of 10 m / min, and “annealing” has a processing temperature of 700 ° C. and a processing speed of 200 m / min. “Comparative Example 1” has a processing temperature of 280 ° C. and a processing speed of 10 m / min, and “Comparative Example 2” has a processing temperature of 520 ° C. and a processing speed of 200 m / min.

The tensile strength is measured by a conventionally known tensile test method. The tensile strength required for the ultrafine polishing wire is 3,000 N / mm ² or more.

  The wire habit is measured by measuring the distance from the upper end to the lower end where the wire is cut to a length of 500 mm, one end is fixed and suspended. It is desirable that the ultrafine polishing line has a distance measured in this way of 450 mm or more.

As a result of measurement, “Example 1” has a tensile strength of 3,900 N / mm ² and a line habit of 450 mm, and “Example 2” has a tensile strength of 3,800 N / mm ² and a wire habit. 480 mm, “Example 3” has a tensile strength of 3,000 N / mm ² and a wire habit of 490 mm, both of which have the necessary tensile strength and straightness.

In contrast, “Comparative Example 1” has a tensile strength of 4,180 N / mm ² and a wire habit of 300 mm, and the wire habit is too small. “Comparative Example 2” has a tensile strength of 1,600 N / mm ^2. The wire habit is 490 mm, and the tensile strength is insufficient.

The “original wire” has a tensile strength of 4,100 N / mm ² and a wire habit of 250 mm. In this case, the line habit is too small. In the case of the conventional “roller straightening”, the tensile strength does not decrease, but breakage often occurs during the straightening process. In the case of “annealing”, the wire habit is 480 mm, which is an allowable level, but the tensile strength is significantly reduced to 1,300 N / mm ² .

Claims (2)

A method for manufacturing a wire for ultrafine polishing with a wire diameter of 0.010 to 0.050 mm using a piano wire as a raw material, characterized in that the wire after the final wire drawing is subjected to a low-temperature annealing treatment at a temperature of 300 to 500 ° C. A method of manufacturing a fine polishing wire. 2. The method for producing an ultrafine polishing wire according to claim 1, wherein the low-temperature annealing treatment is performed by applying tension in an inert gas atmosphere.