JPS5825604A - Manufacture of feedthrough sealed with resin - Google Patents

Abstract

PURPOSE:To improve damp-proof properties, and to obtain a feedthrough suitable for a submarine optical repeater, by forming a hydrophobic resin film by plasma polymerization on at least one surface of sealing resin after injecting the sealing resin into a feedthrough mold and then curing it. CONSTITUTION:A feedthrough 5 is mounted on a sample base 24 and inserted into a chamber 11, and it is installed at the center part between electrodes 12A and 12B. Then, the opening 11A of the chamber 11 is sealed airtightly with a cover 25 and an O ring 26. For this purpose, while a valve 19 is closed and a valve 15 is opened, a vacuum pump 13 is operated to adjust the pressure in the chamber 11 until a capacitance gauge 14 indicates 10<-1>Torr while the flow rate of tetrafluoroethylene gas is equal to that of argon gas. After the presure in the chamber 11 becomes steady, 30W electric power is supplied between the electrodes 12A and 12B from a 13.56MHz high frequency power source 22 through a matching network 23. Every time the electric power is supplied to the electrodes 12A and 12B for one minute, a polymerized film 31 of polytetrafluoroethylene with an about 500Angstrom thickness is formed.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method of manufacturing a resin-sealed feedthrough for use in submarine optical repeaters, etc., and particularly to a method of manufacturing a resin-sealed feedthrough that has excellent moisture resistance and prevents deterioration of the sealing resin. This relates to a manufacturing method.

As a method of fixing an optical fiber to a feedthrough, there is a method of injecting a thermosetting resin into the feedthrough and curing it to seal it. This resin sealing method has the advantage of strong retention of the optical fiber and good workability, but on the other hand, it also has the disadvantage of poor moisture resistance. In this resin sealing method, epoxy adhesive is mainly used, but due to its characteristics, over time, moisture gradually enters the feedthrough through the resin itself or between the optical fiber and the resin. The results reached within the submarine optical repeater.

This will lead to an increase in the relative humidity of the repeater.

FIG. 1 shows a cross section of an example of a conventional resin-sealed feedthrough. In FIG. 1, l is a metal feed-through type that is fixed to the metal case (not shown) of the repeater by soldering or the like. This feed-through type has a tapered hole 2 for passing through the optical fiber, and an optical fiber 3 is inserted into the hole 2.
The bare core 3' from which the cladding has been removed is penetrated, and 1 tk of sealing resin is injected into the tapered hole 2, and this sealing resin≠
Feed-through type 1. Optical fiber 3 and its core 3
′ to be glued. Here, the reason why the bare core 3' is bonded with the sealing resin 4 is that the cladding has high moisture permeability and is therefore not suitable for sealing. In FIG. 1, the upper side of the feedthrough is the cable side, and the lower side is the inside of the repeater.

In such a structure, moisture outside the feedthrough is absorbed through the sealing resin j itself, the bonding surface between the sealing resin ≠ and the feedthrough type l, or the bonding surface between the sealing resin μ and the optical fiber 3 and core 3'. There is a problem with infiltration. That is, the conventional resin-sealed feedthrough has a drawback of poor moisture resistance.

Therefore, a method of forming a hydrophobic resin film on the surface of the sealing resin μ may be considered. For example, fluorine-based resins with low moisture permeability and water absorption, such as Teflon and trifluorochloroethylene, or general thermoplastic resins, such as polyethylene, are hydrophobic resins and can be used as hydrophobic resin films; Because it is a polyurethane resin film, it has poor adhesion to adherends and is difficult to coat. When coating a feedthrough with this type of hydrophobic resin, it is necessary to prevent moisture from permeating through the bonding surface between the coated hydrophobic resin and the feedthrough, so the adhesion is extremely poor. This is a major factor.Also, even minute holes in the coated hydrophobic resin can cause moisture permeation, so it is also necessary to apply a coating without pinholes.

The present invention aims to eliminate such drawbacks by injecting a sealing resin into a feed-through mold, curing it, sealing with the resin, and then applying plasma polymerization to at least one surface of the sealing resin. It is an objective of the present invention to propose a method for manufacturing a resin-sealed feedthrough using a hydrophobic resin coating device.

Hereinafter, the present invention will be explained in detail based on the drawings.

FIG. 2 shows an example of a resin-sealed feedthrough manufacturing apparatus used in the manufacturing method of the present invention, where ll is the electrode /2 A and /
2B is equipped with a plasma polymerization chamber, /3 is a rotary vacuum pump that evacuates the inside of chamber l/, and l is a valve /
3 is a capacitance gauge connected to chamber l/ to measure the pressure inside chamber l. Also,/
4 is a tetrafluoroethylene gas reservoir, and /7 is an argon gas reservoir, which can be supplied to chamber l/ through flow meters /IA, /gB and valves /qΔ, /woB, respectively. 〃 is a cold trap, 2/ is a liquid nitrogen bath, and these trap the tetrafluoroethylene gas and argon gas flowing out from the chamber 11,
These gases are prevented from flowing into the pump 73. On the other hand, the sword is, for example, /3. jA MHz high frequency power supply, in this example, it supplies power of 1, for example, 3θW to the electric power /2A and /2B through the matching network n, and
Polymerization of tetrafluoroethylene is carried out in the reactor.

Using the feedthrough hydrophobic resin coating apparatus (plasma polymerization apparatus) configured as described above, a resin-sealed feedthrough coated with a hydrophobic resin can be manufactured in the following manner.

In other words, the feedthrough configured as shown in Figure 1! is placed on sample stage 2g, inserted into chamber 11, and placed so as to be located at the center of electrodes 12Δ, /2B.

Next, the opening //A of chamber l/ is hermetically sealed with lid B and O-ring I. Now, with Pulp/Li closed and Pulp/S opened, vacuum pump/3 is operated to evacuate chamber L/, and the value indicated by Capacitance Gauge/+ is 10 Torr. .

Next, Pulp/9 is gradually opened, and the flows of tetrafluoroethylene gas and argon gas passing through flowmeter/I (j) are equal, and the indicated value of capacitance gauge/I is equal to /θ Torr. Adjust the pressure in the chamber l/. At this time, the tetrafluoroethylene gas and argon gas flowing out of the chamber/l are trapped by the cold trap and the liquid nitrogen bath 21 to prevent these gases from flowing into the pump 13.

After the pressure in the chamber l/ is steadily /θ 〒orr, /3. j't ■ (y, 3θW power is applied from the high frequency power supply n to the electrodes /2A, /2B via the matching network 23. For each minute of current conduction time to the electrodes /2A, /, 2B, the thickness is approximately SOOΔ A polymer film 3/ of polytetrafluoroethylene was formed.

FIG. 3 shows a feedthrough 3θ constructed by forming a polytetrafluoroethylene film 3/ as a hydrophobic resin film on at least one surface of the sealing resin≠. Here, the same parts as in FIG. 1 are given the same reference numerals, and their explanation will be omitted.

In addition, (6) Lolotrifluoroethylene gas was used in place of tetrafluoroethylene gas under the same conditions as described above. By flowing chlorotrifluoroethylene gas at j times the flow rate, a polymer film 31 of black triple fluoroethylene is formed on the surface of the sealing resin ≠ at a thickness of about 330 A per minute to form a feedthrough 3θ. I could do that.

In this way, the polymer film formed by the above-mentioned plasma polymerization method has extremely good N adhesion properties compared to other coating film formation methods, and has excellent N adhesion properties such as hydrophobic polymers such as polytetrafluoroethylene and polychlorotrioleoethylene. It was also possible to easily coat the resin film. Furthermore, the film thickness of the hydrophobic resin can be freely changed, and a film without pinholes can be formed.

Therefore, according to the present invention, a hydrophobic resin film is formed by plasma polymerization, and a resin-sealed feedthrough with excellent moisture resistance can be easily obtained.

As explained above, according to the present invention, the moisture resistance, which has been a problem in the past, is greatly improved in resin-sealed feedthroughs, so when the present invention is applied to feedthroughs for submarine optical repeaters, teeth.

This has the advantage of greatly improving the reliability of submarine optical repeaters. Note that, of course, if a hydrophobic resin film is similarly formed on each of the surfaces at both ends of the sealing resin, the moisture resistance can be further improved.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing an example of the configuration of a conventional resin-sealed feedthrough, FIG. 2 is a configuration diagram showing an example of a plasma polymerization apparatus used in the production method of the present invention, and FIG. FIG. 2 is a cross-sectional view showing an example of the structure of a resin-sealed feedthrough formed with a film. l...Feed through type, 2...Taber hole. 3... Optical fiber, 3'... Core, t... Resin,
j...Feed through. //...chamber, //Δ...opening. 72A, /λB... Electrode, /3... Vacuum bonder, /
G...Capacitance gauge, B, /9A, /9B...Valve. /6... Tetoshifluoroethylene gas reservoir, /7.
...Argon gas reservoir. /KA, /173...flow meter, 〃...cold trap, 21...liquid nitrogen bath, 〃...high frequency power supply, n...matching circuit network, 2g...sample stage, r ...Lid, 12≦・
...Q-link, 3θ...feedthrough 137...
・Hydrophobic resin membrane. Patent applicant: Nippon Telegraph and Telephone Public Corporation

Claims (1)

[Claims] Pass the optical fiber through the hole drilled in the feed-through type,
A sealing resin B¥1 is injected into the hole and cured to fix the optical fiber in the feed-through mold with the sealing resin, and after sealing, pressure is applied and plasma is applied to at least one surface of the sealing resin. A method for producing a hatsumode sealing feedthrough, which is characterized by forming a hydrophobic resin film through polymerization.