JP3722360B2 - Vibration membrane for electrostatic electroacoustic transducer - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a diaphragm for an electrostatic electroacoustic transducer, and more particularly to a diaphragm for an electrostatic electroacoustic transducer in which a titanium thin film and a nickel thin film are formed on the surface of an ultrathin film made of a synthetic resin.
[0002]
[Prior art]
The electro-acoustic transducer's vibration film is conventionally formed by applying a resistance heating vapor deposition technique to the surface of an ultra-thin film made of a synthetic resin such as polyphenyl sulfide (PPS) or polyethylene terephthalate (PET). It was composed by. However, the film formation of the nickel thin film on the surface of the ultrathin film by the resistance heating vapor deposition technique is poor in mass productivity, and it is difficult to say that the manufacturing cost of the configured vibration film is low. The nickel thin film formed on the surface of the ultra-thin film is likely to have uneven thickness, and the resonance frequency varies greatly as the vibration film. In addition, nickel thin film has poor weather resistance, and in particular, exhibits a heat loss phenomenon that deteriorates due to radiant heat. Therefore, it is inappropriate to use this vibration film as a vibration film for electroacoustic transducers exposed to high temperatures. .
[0003]
An ultra-thin film in which aluminum is used instead of the above nickel as a metal material formed as an electrode thin film on the surface of the ultra-thin film is also used as a vibration film of an electroacoustic transducer. Here, since the aluminum thin film formed on the ultrathin film may be peeled off, an acrylic resin protective thin film is formed on the surface of the aluminum thin film to cope with the peeling. However, the manufacturing method of the vibration film that forms an aluminum thin film on an ultrathin film and protects it by forming an acrylic resin protective thin film is poor in mass productivity, and the formed aluminum thin film and acrylic resin protective thin film It is difficult to form a uniform thickness, and this variation in film thickness cannot be eliminated.
[0004]
[Problems to be solved by the invention]
In this invention, instead of adopting aluminum as a metal material to be formed as an electrode thin film on the surface of an ultrathin film made of a synthetic resin, a titanium thin film and a nickel thin film are formed on the surface of the ultrathin film by a sputtering film forming method. Providing a diaphragm for electrostatic electroacoustic transducers with excellent weather resistance, high mechanical strength, ultra-light weight, low sensitivity, wide variation in frequency characteristics over a wide band that eliminates the above-mentioned problems by forming a film To do.
[0005]
[Means for Solving the Problems]
Claim 1: A titanium thin film is formed on the surface of an ultrathin film made of a synthetic resin by sputtering, and a nickel thin film is formed on the surface of the titanium thin film by sputtering, or a nickel thin film is formed by sputtering. A vibrating membrane for an electrostatic electroacoustic transducer was formed by depositing a titanium thin film on the surface of a nickel thin film by sputtering.
According to claim 2, in the diaphragm for an electrostatic electroacoustic transducer according to claim 1, the ultrathin film is for an electrostatic electroacoustic transducer made of a polyphenyl sulfide or polyethylene terephthalate film having a thickness of about 2μ. A vibrating membrane was constructed.
[0006]
Further, in the electroacoustic transducer diaphragm according to any one of claims 1 and 2, the thickness of the nickel thin film or the titanium thin film is 50 A ° or more. A vibrating membrane was constructed.
Furthermore, in the vibration film for an electroacoustic transducer according to any one of claims 1 to 3, the titanium thin film is formed to be rich in titanium and the nickel thin film is made thicker than the titanium thin film. Thus, a vibrating membrane for an electrostatic electroacoustic transducer having a small thickness compared to the above was constructed.
[0007]
DETAILED DESCRIPTION OF THE INVENTION
An embodiment of the present invention will be described with reference to the examples of FIGS. FIG. 1 is a perspective view of the entire sputtering deposition apparatus, and FIG. 2 is a diagram for explaining the inside of a vacuum chamber in which sputtering deposition is performed.
Reference numeral 1 denotes a vacuum chamber of a sputtering vapor deposition apparatus, and 100 denotes a film supply scraping apparatus. The vacuum chamber 1 is installed and fixed on the base 200. The vacuum chamber 1 is provided with a first cathode 6. A Ti target 61 is attached and fixed to the first cathode 6. A second cathode 7, which is another cathode, is attached at a position symmetrical with respect to the central axis of the vacuum chamber 1. A Ni target 71 is attached and fixed to the second cathode 7. The film supply and removal apparatus 100 is attached and fixed to a carriage 101 and is configured to run on a running rail 110 laid on the base 200. The traveling rail 110 extends to the place where the vacuum chamber 1 is installed and fixed, and the carriage 101 is caused to travel with respect to the vacuum chamber 1 and the film supply scraping device 100 is inserted into the vacuum chamber 1 as shown in FIG. Alternatively, the film supply scraper 100 can be pulled out of the vacuum chamber 1 to the state shown in FIG. The cart 101 is operation-controlled via the travel operation panel 102.
[0008]
Here, in particular, referring to FIG. 2, this shows a cross-section in a state where the carriage 101 is moved with respect to the vacuum chamber 1 and the film supply scraper 100 is inserted into the vacuum chamber 1. Reference numeral 2 denotes a roll-shaped ultrathin film made of a synthetic resin described after being wound around the supply roll 21. Reference numeral 22 denotes a first supply pulley that guides the ultrathin film 2, and reference numeral 23 denotes a second supply pulley that similarly guides the ultrathin film 2. Between the first supply pulley 22 and the second supply pulley 23, the bombard processing device 8 is positioned and fixed. The bombard processing apparatus 8 is composed of a plasma generator, and cleans the surface of the ultrathin film 2 which is disposed downstream of the supply roll 21 by hitting the surface with plasma. Reference numeral 24 denotes a third supply pulley, to which a pinch roll indicated by 241 is attached. Reference numeral 5 denotes a cooling roll positioned at the film deposition unit, 25 denotes a first scraping pulley, 26 denotes a second scraping pulley, 27 denotes a third scraping pulley, and 28 denotes a scraping roll.
[0009]
The first cathode 6 of the sputtering vapor deposition apparatus is attached to the vacuum chamber 1 as described above, and is inserted into and accommodated in the vacuum chamber 1 and pulled out from the vacuum chamber 1. When the first cathode 6 is inserted into the vacuum chamber 1, the first cathode 6 is positioned with the Ti target 61 facing the peripheral surface of the cooling roll 5. The second cathode 7 of the sputtering vapor deposition apparatus is also inserted and accommodated in the vacuum chamber 1 and pulled out from the vacuum chamber 1. When inserted into the vacuum chamber 1, the second cathode 7 is positioned with the Ni target 71 facing the peripheral surface of the cooling roll 5 downstream of the ultrathin film 2 supplied as viewed from the first cathode 6. Is done. The above target 61 of the first cathode 6 can be replaced with nickel, and the target 71 of the second cathode 7 can be replaced with titanium.
[0010]
Next, a method for forming an electrode thin film on the ultrathin film 2 will be described. Prior to inserting and housing the film supply and removal apparatus 100 in the vacuum chamber 1, the ultrathin film 2 is wound around the supply roll 21 to form a coiled film, the coiled film is drawn out, and the first Supply pulley 22, bombard treatment device 8, second supply pulley 23, third supply pulley 24, cooling roll 5, first scraping pulley 25, second scraping pulley 26, and third scraping pulley 27 is set on a scooping roll 28 through 27. As the ultrathin film 2, an ultrathin film of polyphenyl sulfide or polyethylene terephthalate having a thickness of about 2 μm is used. The ultra-thin film 2 is cut into a width of about 500 mm and a length of about 10,000 mm, and is wound around the supply roll 21. When the ultra-thin film 2 is wound and set on the supply roll 21, the carriage 101 is made to travel with respect to the vacuum chamber 1, and the film supply scraper 100 on which the ultra-thin film 2 is set is inserted and accommodated in the vacuum chamber 1. . Then, the Ti target 61 is attached and fixed to the first cathode 6 and the Ni target 71 is attached and fixed to the second cathode 7. The first cathode 6 and the second cathode 7 are fixed in the vacuum chamber 1 as described above. Position to position.
[0011]
Here, after the vacuum chamber 1 is evacuated by a vacuum pump, argon Ar or other sputtering gas is introduced at a pressure of about 10 ¹ to 10 ⁻¹ Pa, and between the Ti target 61 and the Ni target 71 and the cooling roll 5. When DC power is applied with a negative potential, a glow discharge occurs between the two and Ar plasma is generated. Ar positive ions Ar ⁺ in the plasma are accelerated at the cathode potential drop portion in the vicinity of the target, collide with the surface of the Ti target 61 and the surface of the Ni target 71, and the constituent materials are sputtered. The particles of the target constituent material sputtered from the Ti target 61 and the Ni target 71 adhere to the target-facing region on the surface of the ultrathin film 2 supplied to the peripheral surface of the cooling roll 5, and a thin film of the target constituent material is here Will be formed. In order to explain step by step, the ultrathin film 2 reaches the bombard processing device 8 in the process of being gradually pulled out from the supply roll 21 and being scraped off by the scraping roll 28 while being cooled by the cooling drum 2. The bombarded pretreatment is applied. Next, the ultrathin film 2 was rolled back and the surface subjected to the bombarding treatment reached the Ti target 61 of the first cathode 6 in a state along the surface of the cooling roll 5 and was bombarded. The target constituent material particles sputtered from the Ti target 61 adhere to the surface to form a titanium thin film. The ultrathin film 2 is further struck, and the surface on which the titanium thin film is formed is opposed to the Ni target 71 of the second cathode 7 in a state along the surface of the cooling roll 5. Particles of the target constituent material sputtered from the Ni target 71 adhere to the surface of the formed titanium thin film, and a nickel thin film is formed. In this electrode thin film formation process, the temperature of the cooling drum 2 and the operating conditions of the first cathode 6 and the second cathode 7 are appropriately set, and the thickness and other design conditions of the titanium thin film and the nickel thin film are defined. . The thickness of the nickel thin film or the titanium thin film is preferably 50 A ° (angstrom) or more. In particular, when the titanium thin film is formed to be thick and rich in titanium and is a nickel thin film having a thickness smaller than that of the titanium thin film, the vibration film for the electroacoustic transducer is sufficiently reduced in weight. In addition, the vibration membrane can be easily vibrated since it is lightweight, and the sensitivity of the electroacoustic transducer incorporating the vibration membrane is improved.
[0012]
The ultrathin film 2 wound around the supply roll 21 continues from the supply roll 21 to the scooping roll 28, and finally reaches the scooping roll 28. The ultra-thin film 2 is scraped off from the supply roll 21 to the scooping roll 28 while the supply speed is adjusted by the pinch roll 241, and in the middle thereof, the first supply pulley 22, the second supply pulley 23, It is supplied to the surface around the cooling roll 5 that is positioned in the film deposition section via the third supply pulley 24. The ultra-thin film 2 is further scraped off from the peripheral surface of the cooling roll 5 by a scraping roll 28 via a first scraping pulley 25, a second scraping pulley 26, and a third scraping pulley 27. .
[0013]
As described above, the ultrathin film 2 wound around the supply roll 21 is continuously scraped off from the supply roll 21 to the scraping roll 28 while the supply speed is controlled and adjusted by the pinch roll 241. The bombardment processing device 8 is reached while facing the surface, and the surface is subjected to bombardment processing. Next, the surface that is further scraped off and subjected to bombardment processing faces the Ti target 61 of the first cathode 6. Then, a titanium thin film is deposited on the bombarded surface. The ultrathin film 2 is further scraped off, and the surface on which the titanium thin film is deposited is the surface facing the Ni target 71 of the second cathode 7, and the nickel thin film is deposited on the surface of the titanium thin film. Film can be deposited. Eventually, a titanium thin film and a nickel thin film are sequentially laminated on the surface of the ultrathin film 2.
[0014]
【The invention's effect】
As described above, according to the present invention, a vibration film for an electroacoustic transducer having excellent weather resistance, having a very light weight, good sensitivity, high mechanical strength, and a small variation in frequency characteristics over a wide band is configured. be able to.
That is, the vibrating membrane for an electrostatic electroacoustic transducer according to the present invention is formed by depositing a titanium thin film on the surface of an ultrathin film made of synthetic resin by sputtering, and depositing a nickel thin film on the surface of the titanium thin film by sputtering, Alternatively, a nickel thin film is formed by sputtering, and a titanium thin film is formed by sputtering on the surface of the nickel thin film. With this configuration, it is possible to configure a vibrating membrane for an electroacoustic transducer that is light and can ensure sufficient electrical conduction. Since this vibration film is made of a nickel thin film and a titanium thin film, both of which are corrosion-resistant metals, it is stable without deterioration over a long period of time, and it is easy to vibrate because it is lightweight. The sensitivity of the electroacoustic transducer incorporating the membrane is improved.
[0015]
Here, when a titanium thin film is formed on the surface of an ultrathin film made of a synthetic resin by sputtering and a nickel thin film is formed on the surface of the titanium thin film by sputtering, titanium has a specific resistance of 0.478 × 10 ^{−. 4} cm, specific gravity:. 4 while a 50, nickel ^{resistivity:. 6 9 × 10 -6 cm} , specific gravity:. 8 because it is 84, and forming a large titanium rich thick titanium film, titanium By making the nickel thin film thinner than the thickness of the thin film, the electroacoustic transducer vibrating membrane can ensure sufficient electrical conduction while being significantly reduced in weight. In addition, since the vibration membrane is lightweight, vibration is easy, and the sensitivity of the electroacoustic transducer incorporating the vibration membrane is improved.
[0016]
A vibrating film formed by depositing a nickel thin film by sputtering and depositing a titanium thin film on the surface of the nickel thin film by sputtering has the same effect as described above. In addition, since the titanium thin film constitutes the surface layer, the vibration film for an electroacoustic transducer can be further improved in corrosion resistance.
[Brief description of the drawings]
FIG. 1 is a perspective view illustrating an embodiment.
2 is a cross-sectional view of the embodiment of FIG.

Claims (4)

A titanium thin film is formed by sputtering on the surface of an ultrathin film made of a synthetic resin, and a nickel thin film is formed on the surface of the titanium thin film by sputtering, or a nickel thin film is formed by sputtering and the surface of the nickel thin film is formed. A vibration film for an electrostatic electroacoustic transducer, wherein a titanium thin film is laminated by sputtering. In the diaphragm for an electrostatic electroacoustic transducer according to claim 1,
The ultrathin film is made of a polyphenylsulfide or polyethylene terephthalate film having a thickness of about 2 μm. In the diaphragm for an electroacoustic transducer according to any one of claims 1 and 2,
A vibrating membrane for an electroacoustic transducer, wherein the thickness of the nickel thin film or the titanium thin film is 50 A ° or more. In the diaphragm for an electroacoustic transducer according to any one of claims 1 to 3,
A vibrating membrane for an electrostatic electroacoustic transducer, characterized in that a titanium thin film is formed to be thick and rich in titanium and a nickel thin film is a thin film having a thickness smaller than that of the titanium thin film.

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