JPS6043243A - Manufacture of scanning stylus base material - Google Patents

Abstract

PURPOSE:To mass-produce scanning stylus base materials in a uniform shape at high yield by forming plural recessed parts in one surface of a base body longitudinally and laterally at constant pitch, arranging a coupling material and a stylus chip in each recessed part and fixing them to the base body, and cutting the base body between adjacent recessed parts. CONSTITUTION:Soldering materials 5 to which an extremely small amount of titanium for increasing joint strength is added is put in recessed parts 3 of the base body 1, and stylus chips 6 made of diamond are placed thereupon. Then, this base body is mounted on a carbon-made base for preventing the mixture of impurities in a container such as a bell jar, and while the stylus chips 6 are pressed with a pressing jig 7, the base body is heated for 30-60min in a vacuum or inert gas atmosphere above the fusion temperature of the soldering materials, e.g. 800-900 deg.C, thus soldering the chips. Then, the recessed parts are cut individually along center lines between the recessed parts with a wire saw having numbers of wires or a diamond cutter having numbers of wheels.

Description

[Detailed Description of the Invention] G) Industrial Application Field The present invention relates to a method for manufacturing a scanning needle base material for molding scanning needles used in needle contact type disk players such as CHD and VHD systems. be.

(B) Prior art Binding of the base material of the scanning needle used in the signal reference repeating device applied to CED or VHD players that play capacitive video discs. A tiny diamond chip is attached to the titanium base. A composite needle base material bonded to diamond has been proposed to reduce the amount of expensive diamond used.

As shown in Fig. 1, this conventional seed base material has a recess (Pa) in advance at one end of a rod-shaped base (P) made of titanium with a diameter of 1 steel and a length of about 30++1111, and then a second recess (Pa) is formed in advance.
As shown in the figure, diamond (or a gemstone such as sapphire) is formed through the soldering material q, and the sides are 0.15 to 0.
An intermediate product of the base material is obtained by soldering a needle tip (chiributo) with a length of 0.4 to 0.5 mm. but,
If only the tip of this intermediate product is molded and used as a scanning needle, it will be large and heavy, making it impossible to obtain the necessary frequency characteristics during reproduction. Therefore, in order to reduce the size of the needle, a small diameter portion (Pb) as shown in FIG. 3 is provided within a range that can ensure the mechanical strength of the scanning needle. This small diameter part (pb) has a diameter of 0.5'mm and a length of 1
．． 5-2. It is about Oym. The scanning needle base material obtained in this way is then molded into a shape that fits the tip of the tip containing the lip (lt) to the lip of the video disc, and electrodes are attached to the electrode forming surface. It is considered to be a scanning needle as a finished product.

Such conventional manufacturing methods have the following drawbacks. ■The volume of the base that supports the tip is extremely small compared to the starting material, so it requires a long processing time. In addition, there is a lot of material loss, and as a result, it does not contribute to cost reduction of the scanning needle (the loss rate reaches 98.396 if only about 100% of the starting material is actually used). ■Since each substrate is molded individually, the number of man-hours required is large, and there is a limit to the decline in yield. ■Since the base body has a cylindrical shape, it was difficult and time-consuming to set the specific direction of the needle tip when installing it into a pick-up device after it was completed as a scanning needle (signal track of the recording medium hair). For,
In order to maintain durability, it is necessary to specify the direction of the crystal axis of the needle tip.) In addition, it is necessary to define the relative arrangement of the signal tracker on the recording medium and the electrode surface provided on the scanning needle, but the prerequisite for this is the needle tip tip. In practice, it is extremely difficult to determine the relative relationship between a specific crystal direction and the electrode surface because the electrode surface is covered with brazing material (the exposed portion of the needle tip is extremely small). In view of this point, is it possible to partially provide flat parts on the base?1. Although this is effective against the powerful, it is not effective against the latter. Furthermore, this increases the number of man-hours and causes a decrease in yield. ■Since the above-mentioned small-diameter portion is formed by cutting with extremely high impact, the needle tip may fall off or the small-diameter portion may become deformed, causing a decrease in yield. In addition, since the needle tip tip is often fixed eccentrically to the rotating shaft of the base body, the diameter of the cutting part, that is, the small diameter part, where the cutting blade does not come into contact with the needle tip tip must be set with a margin. and its diameter is 0,
The maximum distance was 5m. Therefore, there is a limit to how much weight can be reduced, leading to deterioration of reproduction frequency characteristics mainly due to the weight of the scanning needle.

e＼) Purpose of the Invention The present invention has been made in view of the above points, and has the following features: less material loss, constant crystal orientation of the needle tip, reduced man-hours,
It is an object of the present invention to provide a method for manufacturing a scanning-side base material that can improve yield.

B) Structure of the Invention The present invention provides a plurality of recesses each having a certain width in the vertical and horizontal directions on one surface of the base, and a bonding material and one needle chip are placed in the recesses, Using the binding material, the needle tip
The lip is fixed to the base body, and then the space between adjacent recesses is cut to produce a large amount of square columnar scanning needle base material having a needle tip and lip at the tip.

Example) Figures 4 to 8 illustrate one example of the method of the present invention. For example, the base body (1) has a thickness of 1.5 to 2.0, -
It is a titanium material with sides of 20 to 30 stiffness, - side (1a)
On top, 100 to 150 μm in depth horizontally and vertically with Edobi Sochi (2)
m, - pyramidal recess with sides of 130 to 240 μIn (3)
form. This is formed by pressing with a four-pyramidal presser (4) made of a relatively hard material such as diamond or sapphire.

Here, titanium is selected as the base material because it has excellent brazing properties, processability, heat resistance, and corrosion resistance, and has a light M content. Figure 4 is a perspective view of the base (1) in which recesses (3) are formed vertically and horizontally in this way (for convenience of drawing, the number of recesses is reduced), and Figure 185 shows this. Between the partial planes of the base body, FIG.
The side 1IIj diagram is also shown.

Next, a brazing filler metal (5) to which a small amount of titanium has been added to increase the bonding strength is placed in the recess (3), and a diamond tip (6) is placed on top of the filler metal (5).

Apply one tip to all the recesses in the same way. This substrate is then inserted into the bulge 1. Place it on a carbon base to prevent impurities from entering the container, such as a needle tip (6
) with the pressing jig (7), in a vacuum or inert gas atmosphere at a temperature higher than the melting temperature of the brazing material, e.g. 800~
Brazing is performed by heating at a temperature of 900° C. for 30 to 60 minutes. FIG. 7 is a partial cross-sectional view of the base body showing the state of pressing by the pressing jig, and FIG. 8 is a partial plan view of the base body while the wax liquid is being drained. Due to soldering of the needle tip, if the brazing material flows out only to the land portion of the base il+ as shown by the burr in Figure 8 (case A), or if it rides on the surface of the needle tip (6). (In case B) etc. recess (
Since the inner surface shape of 3) closely matches the outward shape of the needle tip (6), the needle tip (6) is fixed along the recess.

After the soldering process is completed, the base body is cut along the center line between the recesses to separate each recess using a wire wheel with multiple wires or a diamond force/litter with multiple wheels. do. The broken line (8) in Fig. 8 indicates the boundary line with the cutting edge (9b).For example, when using a wire with a wire diameter of 80 μm,
Since the cutting margin has a width of 110 to 115% of the wire diameter, for example, using a substrate with a side of 2.0 m as a starting material,
If one side of the base of the finished product is 0.45 to 0.4, then 1
More than 000 finished products will be obtained.

FIG. 9 is a partially cutaway perspective view of the scanning needle base material manufactured in this manner. In the figure, (6) is the needle tip, (
5) is a brazing material, and (1) is a substrate. In this base material, the needle tip (6) can be correctly attached to the base fi+ by using the recess. A description of the method for manufacturing a scanning needle using this base material as a starting material will be omitted.

In this example, a titanium plate was used as the base material, but it may be made of steel with anti-corrosion treatment on the surface or a lightweight, corrosion-resistant material.
It is also possible to use ceramic brazing material with excellent heat resistance, and in this case, the recess is formed by press molding and fired. Note that it is difficult to solder the ceramic brazing material as it is after firing, so the surface is metallized and then sent to the soldering process.

FIG. 10 shows a partial plan view of the base of another embodiment. This is done by providing a groove 00) adjacent to the recess (3) of the base (1) as an escape route for the solder solder (5) that comes out during the welding process, so that the solder solder can escape onto the needle tip. This is to prevent it from getting too high. FIG. 11 shows a perspective view of a scanning needle base material manufactured using this base body. Figures 12 to 15 all show other embodiments, in which the shape of the joint of the needle tip is devised. In each case, the solid line (C) indicates the needle tip, the solid line (C) indicates the brazing material, and the broken line (C) indicates the area where the needle tip is to be placed. Figures 12 to 14 all aim to improve the adhesive strength between the needle tip and the substrate, and to increase the bonding area between the needle tip and the brazing material.

In FIG. 14, grooves 00) are provided in each recess so as to be independent of each other, and serve as an escape route for the bathed solder.

(F) Effects of the Invention The present invention provides a plurality of recesses at a constant pitch in the vertical and horizontal directions on one surface of the base, and a bonding material and one needle tip are placed in the recesses. The needle tip is fixed to the base using a binding material, and then cut between adjacent recesses to form a J.
Since the scanning needle base material is manufactured in the shape of a square column with a needle tip at the tip, it is possible to easily define the positional relationship of the needle tip and lip with respect to the base material, and the shape can be uniform. scanning Q (base material can be produced in large quantities with good yield).

[Brief explanation of the drawing]

Fig. 1 is a perspective view of a conventional base material for scanning side base material, Fig. 2 is a partially sectional side view showing an intermediate product of a conventional scanning needle base material, and Fig. 6 is a conventional scanning side base material. FIG. Figure 4~
FIG. 9 illustrates one embodiment of the method of the present invention. Fig. 4 is a perspective view of the base, Fig. 5 is a partial plan view of the base, Fig. 6 is an A-A M plane view of Fig. 5, and Fig. 7 is a cross section of the pushing part broken by the pressing jig. It is a diagram. FIG. 10 is a partial plan view of the base of another embodiment, and FIG. 11 is a perspective view of the scanning side base material. FIG. 12, FIG. 13, FIG. 14, and FIG. 15 are all partial plan views of base bodies of different embodiments. Explanation of main drawing numbers (1) Base, (6) needle tip, (3) recess. Figure 1 Figure 2 Figure 8 Figure 6 Figure 4 Figure 9 Figure 11 Figure 12 Figure 13! Figure 14 '151 Procedural Amendment (Voluntary) Commissioner of the Japan Patent Office 1, Indication of the case, Patent Application No. 152522 filed in 1982, 2, Name of the invention, Method for manufacturing scanning needle base material 6, Person making the amendment, Case and Relationship Patent applicant name (188) Sanyo Electric Co., Ltd. 4 Agent address Moriguchi type Keihan Hondori 2nd block 18-5, "Detailed description of the invention" column 6 of the specification subject to amendment, Details of the amendment book! In the sixth line of page $5, "in this way" is corrected to "The small diameter portion (Pb) is then cut from the base (P) and used as the scanning needle base material. In this way."that's all

Claims (3)

[Claims] (1) A step of providing a plurality of recesses with a constant width in the vertical and horizontal directions on one surface of the base, a step of arranging a binding material and a needle tip in each recess, and a step of placing the binding material in the melting and solidifying the needle tip to the substrate;
A method for manufacturing a scanning needle base material, comprising the step of dividing the base body vertically and horizontally in the middle between adjacent recesses. (2) The scanning needle base material according to claim (1), wherein the recess has a shape (for example, a four-sided pyramid) that matches the outer shape of the portion where the needle tip is embedded. manufacturing method. (3) The recesses are provided with communication passages between adjacent ones, and the passages constitute an escape route for the flowing binder. 1)
The method for manufacturing a scanning needle base material according to item (2) or item (2).