JPS6083495A - Diaphragm for electroacoustic transducer and its manufacture - Google Patents

Abstract

PURPOSE:To obtain a speaker with superior characteristics which make the most of merits of a compound structure diaphragm by forming a composition transition layer which has slow transition on the boundary surface between a base made of metal and a surface high-rigidity ceramic layer. CONSTITUTION:The metal used for the base 1 of the diaphragm 1 is formed in a diaphragm shape and the composition transition layer 2 is formed of a compound of oxide ceramic and base metal by a physical vapor deposition (PVD) method. The high-rigidity ceramic layer 3 is formed on the surface of the transition layer 2 by the PVD method. Consequently, a diaphragm which has density rho nearly equal to that of the metal layer of the base 1, a Young's modulus E nearly equal to that of the ceramic, and extremely large specific strength E/rho is obtained. Further, the transition layer 2 is formed of the compound of the base metal and surface ceramic, so it combines with both layers in extremely close contact and the cracking and separation of the ceramic layer are eliminated completely.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a diaphragm for an electroacoustic transducer, particularly to an improvement of a composite material diaphragm having a metal base and a method for manufacturing the same.

In general, diaphragms for audio equipment are made of materials with a low density ρ and a large Young's modulus d, in order to widen the reproduction frequency band, prevent splitting, and improve frequency characteristics. It is a matter of common knowledge to judge each and every cut of the diaphragm. However, the following plate made of a single material has a limit in its rigidity. A: l - Since it is not possible to obtain sufficient performance, two or more types of materials are combined to reduce the apparent density of the cow #. Apparently, a diaphragm with a high Young's modulus is interposed. One type of diaphragm with such a composite structure is a diaphragm having a configuration in which a highly rigid ceramic material is adhered to the surface of a low-density metal. This fine movement plate has a large apparent Young's modulus E and low density, so it has an extremely high specific strength F/ρ, but due to the difference in the number of thermal expansion threads between the base metal and the ceramic material, Due to cracks in the layer or peeling, it was not possible to fully demonstrate its performance and it could not be put to practical use.

This invention takes advantage of the characteristics of a composite diaphragm, and the composite 111
The present invention relates to a vibration board for electrical back-resonance equipment that eliminates the drawbacks seen in the conventional example by improving the four-structure structure, and a method for manufacturing the same.

The method for manufacturing a J-diaphragm plate according to the present invention includes: (1) A step of molding a metal that will become the base 1 of the diaphragm into a diaphragm shape.

(2) Physical vapor deposition method (PVD method) on the substrate 1
Step (3) of forming a composition transition layer (2) made of a compound of an oxide thread ceramic and a base metal by forming a highly rigid upper ramic layer (3) on the surface of the composition transition layer 2 by the P VD method. A reaction process to form a link is suitable. That is, in FIG. 1, 4 is the diaphragm base;
5 is a target, 6 is a vacuum container, 7 is a high frequency power source, 8.
8' is a waste supply (grain), and 9 is a vacuum pump.

J (The sliding plate obtained in the manner of Jt is made of metal as shown in Figure 2) 1 (1) on the surface of the body 1) I'f, "1 rigid ceramic Since layer 3 is formed, the density ρ is almost the same as that of the base metal, and the Young's modulus E is approximately the same as that of ceramic, and (Y1%
This results in a diaphragm with a large specific strength F/ρ. History [ha1
Since the composition transition layer (2) is a compound of the base metal and E7 on the surface, it is bonded to each layer at W'& JX contact, and has a structure in which the material transitions continuously from metal to ceramic. Therefore, cracks and peeling of the ceramic layer, which were observed in the conventional example, are completely eliminated. Base metal AA'! A may be a light metal such as aluminum, magnesium, or titanium, or other corrosion-resistant stainless steel. Ceramic threads such as oxide threads, nitride threads, or carbide threads give good results.

Next, the manufacturing method and results will be further described with reference to Examples.

〔Example〕

In FIG. 1, an IV4g alloy foil having a thickness of 100 μm is formed into a diaphragm shape to serve as a diaphragm substrate 4, and S]02 is placed in a vacuum vessel 6 at a temperature of 1 heat/l· with a target layer 1-5. Next, the inside of the vacuum container 6 is placed at a vacuum level of 1O-7 Torr and a temperature of 300.
After baking at ℃, the gas supply length is 8.8'.
Flow Ar gas from ...... M10 me/m
in, Oz force ゛nu 01m1! /min into the vacuum vessel, respectively, and the pressure was increased to 1.5 x 10-
Adjust the pressure to 2 Torr. Next, adjust the fine movement plate base and 51
02 Apply 600W of power between the tarp and throat for 20
An intermediate transition layer (15 .mu.m) having a composition of Mg25104 was formed on the Mg alloy compliant plate substrate by interlinking with a reactive powder for a minute. Next, 0 in the container
2 gas] and introduced only Ar scum, and the pressure J was set to 1. By performing a solar link between approximately IIl and lI under the conditions of OX 10-2 Torr and power of 600 W, a ceramic layer consisting of Sing (
19 x 10μ) is formed and the vibration is completed. Third
The figure shows the shear stress J (a value that is a guideline for the adhesion force between the two layers) between the metal substrate 1 and the ceramic layer 3 by changing the thickness of the composition bath transfer layer 2. The case where the thickness of the transition layer 2 is 0 is a conventional example, and is a part that resembles a person and is directly attached to the body. In Example 1, the strength of the ceramic layer is approximately three times that of the conventional example, and the compositional transition 'dJ' of 44 is observed.

The 4-axis sliding plate obtained by the method of the present invention is a composite 4'fI plate coated with a ceramic material that is conventionally available.
'lUnlike the diaphragm, the base metal and surface ceramic 4J
Composition between the material layer 3. Because of the intervening layers, the adhesion between the base and the surface layer is strong at the fourth layer, and by fully utilizing the advantages of the composite structure diaphragm, it is possible to create a speaker with excellent characteristics.

[Brief explanation of drawings]

FIG. 1 is a block diagram of a reactive sputtering apparatus, FIG. 2 is a partially enlarged sectional view of a perturbation plate of the present invention, and FIG. 3 is a characteristic diagram of intercostal shear stress. Stiffness 1 is the substrate, 2 is the composition transition layer, and 3 is the high-particulate ceramic layer. 1) Figure 5 Group Ii & l Slight change 1・Death; Momme l-1 Temple 3)' 0 (μ)

Claims (1)

[Scope of Claims] 1. At the interface between the base (1) made of metal and the high-rigidity cefmic layer (3) on the surface, the composition of the high-rigidity ceramic layer (3) changes from the metal of the base (1). A micro-tremor plate for an electro-acoustic transducer, characterized in that the composition of which gradually changes to the ceramic composition of ) also forms a shifted layer (2). 2. The diaphragm for an electroacoustic transducer according to claim 1, wherein the highly rigid ceramic layer (3) is made of an oxide thread ceramic material. 3. The diaphragm for an electric guitar transducer as set forth in claim 1, wherein the high-rigidity ceramic layer (3) is made of a carbide-based ceramic. 4. The diaphragm for an electroacoustic transducer according to claim 1, wherein the highly rigid ceramic layer (3) is made of a nitride yarn ceramic material. 5 A step of forming metal into a predetermined retractable plate shape, and a step of forming a base member on the surface of the base member (1) of the retractable plate obtained through this step by physical vapor deposition method (hereinafter abbreviated as PVD method). (
Step 1) of forming a composition transition layer (2) consisting of a compound of the metal forming oxide thread ceramic fiber silk, and forming a high-rigidity cefmic layer on the surface of the composition transition layer (2) by a PVD method. A method for manufacturing a diaphragm for an electroacoustic transducer, comprising a step of forming it. 6. The method of manufacturing a diaphragm for an electroacoustic transducer according to claim 5, characterized in that the near+1 frequency Nupanotarinok method is used as the PVD method.