JPS59112449A - Electrostatic capacity type reproducing stylus for video disk - Google Patents

Abstract

PURPOSE:To raise a mass-productivity by forming a masking material for etching a supporting body by the same pattern as an electrode, between the supporting body and the electrode. CONSTITUTION:The tip part which required wear resistance is formed by a hard film 3, and a supporting body 4 and an electrode 2 are added to it as the structure. First of all, an SiO2 film is patterned to the surface of an Si substrate, subsequently, the etching is executed to the middle, and thereafter, Ti being an electrode material 2 is vapor-deposited, and the electrode is patterned. Subsequently, the tip part of the stylus is formed by etching the Si substrate, and in the end, a hardening film 3 of a boron nitride thin film is formed. Accordingly, the electrode 2 and a masking material 5 are of the same pattern, and the SiO2 film is removed from the surface on which the boron nitride thin film is formed, therefore, peeling of the boron nitride film, etc. are reduced, and a mass-productivity can be raised.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a capacitive playback needle for video discs.

[Prior art]

Capacitive method ρ records video and audio signals on a recording medium as changes in geometric shape, and uses a playback needle to detect the recorded video and audio signals again as changes in capacitance.
The conventional structure and manufacturing method of the playback needle in a video disc will be explained below with reference to FIGS. 1(a) and 1(b). Note that FIGS. 1(a) and 1(b) are perspective views showing conventional regenerated needles, respectively.

There are two main types of capacitance methods for video discs:
There are several types. In other words, a) a type with grooves like an audio record, and b) a type without grooves as opposed to a) above.

However, when looking only at the two regenerated needles, although the shape of the needle tip 7 for signal detection is slightly different, the constituent elements are almost the same. In other words, the playback stylus is made of a material such as diamond 1, which has excellent abrasion resistance because it comes into contact with the high-speed rotating disk surface when detecting signals from the disk surface. An electrode material 2 for performing detection is formed, and further,
In both types a) and b) above, in order to faithfully detect changes in the capacitance recorded on the disk even if the regeneration needle is slightly worn, the regeneration needle itself or the electrode width has been devised. In figure a), the width-dimension Wa of the electrode tip is 2 μm, the thickness Ha of the diamond material tip is 4 μm, and in figure b), the width dimension wb is 1 μm.
The 1 μm dimension Hb is 10 μm.0 However, both types a) and b) have the following disadvantages when viewed from the viewpoint of the manufacturing process of recycled needles.

It is extremely difficult and almost impossible to process a large number of diamond materials used as recycled needle materials at once.

Therefore, it is necessary to process and form electrodes on each regenerated needle, which has a great impact on improving mass productivity.

[Purpose of the invention]

SUMMARY OF THE INVENTION An object of the present invention is to provide a regenerated needle having a structure that eliminates the drawbacks of the conventional technology in the regenerated needle manufacturing process and enables improved mass production.

[Summary of the invention]

In order to achieve the above object, the present invention provides a regenerated needle comprising an electrode on a support and a hard thin film formed thereon, and a mask material for etching the support is provided between the support and the electrode. 'It was formed in the same pattern as the electrode opening.

In order to eliminate the drawbacks of conventional techniques in improving mass productivity, we considered using photolithographic technology in the same way as in the manufacture of ICs and the like. As an example of the structure of a regenerated needle that realizes this, a structure as shown in a perspective view in FIG. 2 is used. That is, in FIG. 2A, which is a front view seen from the tip of the needle in the same figure, the tip, which directly contacts the disk surface and requires wear resistance, is formed of a hard film 3, and the support 4, A regenerated needle having a six-layer structure including an electrode 2 and having performance equivalent to that of the prior art is obtained. With the above structure, substrate processing becomes possible, and the problem of improving mass productivity, which is a drawback of the conventional technology, is solved.

Adhesive strength between each material is important as a condition for obtaining a recycled needle with the above structure. These materials include boron nitride (BN) for the hard thin film 6.

thin film, titanium (Ti) thin film for electrode thin film 2, S for support 4
When the 8102 film is used as the mask material 5 during etching of the i-substrate and furthermore the Si substrate, the hard thin film 3 is formed on the mask material 5 of 5iOz and the electrode thin film 2 of Ti, as shown in FIG. 2A. Ru. However, the hard thin film filter made of BN is stable as a hard film on the electrode thin film 2 made of Ti, but the mask material 5 made of S]02 film is stable as a hard film on the electrode thin film 2 made of Ti.
However, it has been difficult to obtain the desired regenerated needle because the membrane is unstable and brittle.

For this reason, as a result of examining materials that are compatible with the hard thin film 6 made of BN, it was found that a Si substrate is one of the good materials. Therefore, the main point of the present invention is that 5iOz
The goal is to create a structure that does not involve That is, 5iOz
[Embodiment of the Invention] As an embodiment of the present invention, a video disk consisting of a hard thin film, an electrode thin film, and a support body is etched so that the mask material 5 consisting of a film matches the flap of the electrode 2. The manufacturing process for making recycled needles will be described below with reference to FIG. 6.

As the material of the support 4, 8102 as a mask material is formed in a thickness of about 15 μm on both sides of the substrate.
A substrate was used. Note that the plate thickness was approximately 300 μmt.

That is, first, the SiO2 film on the opposite side of the Si substrate on which the BN thin film was formed was patterned. Next, add this to 66
%K OH aqueous solution and partially subjected to crystallographic anisotropic etching. Next, using the electrode materials 2 and 1, Ti was steamed at 1111 K for about 02 μm to form a BN thin film, and an electrode pattern having a width of 10 μm was patterned. Thereafter, the Si substrate was further etched to form a regenerated needle tip.

Thereafter, the SiO2 film on the BN thin film forming surface side other than the Ti electrode was removed using a plasma etching device (CF4 gas) to align the SiO2 film with the electrode button. Next, a BN thin film having a thickness of approximately 40 μm was formed.

The re-main needle tip formed on the 2〃φ (100) Si substrate by the above method is diced into a regenerated needle shape using a dicer,
The tip of the obtained playback needle was polished to obtain a playback needle for video discs.

FIG. 4 shows a front view of an embodiment of the present invention seen from the tip of the regenerated needle. In the figure, it can be seen that the electrode 2 and the mask material 5 have the same pattern.

As described above, since the 5iOz film was removed from the surface on which the BN thin film was formed, peeling off of the BN thin film was reduced.
Although an O2 film is used, it is not necessary to limit it to S t 02, and Si
It can be applied to materials that can be used as mask materials.

Further, although the above description has been made regarding a reproducing needle for a video disc of a type without grooves, the present invention can also be applied to a type with grooves.

〔Effect of the invention〕

The present invention has made it possible to supply a playback needle for video discs with a layered structure that can be expected to improve mass productivity.

[Brief explanation of the drawing]

FIGS. 1(a) and 1(b) are perspective views showing conventional regenerated needles, FIG. 2 is a perspective view of a regenerated needle devised in the process leading to the present invention, FIG. 2A is a front view of the same, and FIG. The figure is a process explanatory diagram showing a manufacturing process according to an embodiment of the present invention, and FIG. 4 is a front view showing an embodiment of the present invention. Symbol explanation 1...Diamond material etc. 2...Electrode 6...Hard thin film 4...Support 5...Mask material 6.7...Needle tip part mostly 1 Figure 2 Figure 2 △ Da Figure 3% 4 Flash

Claims (1)

[Claims] 1) A capacitive playback needle for video discs comprising an electrode on a support and a hard thin film formed on the electrode,
A capacitive playback needle for a video disc, characterized in that a mask material for etching the support is formed between the support and the electrode in the same pattern as the electrode.