JPS59226417A - Corrosion resistant electrode structure - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an electrode structure in which metal is deposited directly on a plastic film, sheet, or molded product, or an electrode structure obtained by transferring the metal onto the material.

In recent years, polyester films with direct vapor deposition of aluminum, zinc, copper, etc., or vapor deposition of these metals, have been used as contact materials used in office electronic equipment, household electrical equipment, etc., or as shielding films for flat cables. Membrane transfer products are used. For example, when such an electrode structure is used as a contact electrode material, the contact portion directly affects the performance of the device, and is required to be able to turn on and off electrical signals without causing even the slightest malfunction.

However, recently, as the environments in which these devices are used have become more diverse, there are more opportunities for malfunctions to occur.

In general, contact materials such as keyboards have low surface resistance for conductivity, stability of the metal film surface against various atmospheres (corrosion resistance), and good workability due to adhesive attachment, etc.
and quality stability are required. It is also required to have stability against constant use, for example, that the deposited film does not disappear due to electric current. However, in the case of aluminum vacuum-deposited polyester film, which is currently considered to have the most practical potential, it has low surface resistance, productivity,
Although the dimensional stability due to heat treatment is within a satisfactory range,
Due to corrosion resistance and the loss of the deposited film due to intermittent current application, it cannot be put into stable practical use as it is. In addition, especially when the aluminum-deposited polyester film is used as a keyboard component by pasting it on various foam materials, solvents, adhesives, drying heat, etc. during the pasting process may affect the aluminum-deposited surface. A deterioration phenomenon occurs in which the surface resistance value increases.

In view of the current situation, the present inventors have made extensive studies and have discovered an electrode structure that is highly stable against the atmosphere.

That is, the present invention provides plastic films, sheets,
Alternatively, a first vapor deposition layer of aluminum, aluminum, copper, etc., which is a metal with low specific electrical resistance, is provided on the molded product, and then a layer of chromium, nickel, nichrome, stainless steel, Hastelloy alloy, or titanium, which is a metal that is easily passivated, is provided on the molded product. The present invention provides an electrode structure characterized in that a second vapor deposited layer is provided, and an electrode is constituted by a conductive layer made of a combination of the first and second vapor deposited layers.

Hereinafter, the content of the present invention will be explained using the drawings.

Figure 1 shows that a first vapor deposition layer 2 with low surface resistance is formed on a polyester film 1 by ordinary air vapor deposition, and then a second vapor deposition layer 3 is formed by electron beam heating or sputter deposition. It is a cross-sectional view.Generally, considering the first vapor deposition layer 2 as a current-bearing part, the vapor deposited metal has a specific electrical resistance smaller than 1010 x 10 (ohm-am) and has a low surface resistance after vapor deposition such as aluminum or zinc. or copper is preferable. However, if the film is deposited too thickly in order to lower the surface resistance, it has the disadvantage that the adhesive force with the substrate becomes weak. Therefore, as the @1 deposited layer 2, the thickness The surface resistance of
According to. ) is the most preferable range, but it can of course be used in cases where the resistance is higher than this range. Further, the second vapor deposited layer 3 that protects the first vapor deposited layer 2 from the external atmosphere is a vapor deposited layer of a metal that is easily passivated in an oxygen atmosphere, such as titanium, chromium, nickel, stainless steel, Hastelloy alloy, nichrome, etc. Although it is preferable that the thickness be thicker, from a practical standpoint in consideration of productivity, a range of 10 to 1000 Ω/hole is preferable, which is the minimum necessary level to be expected to be effective.

In the case of the basic configuration shown in Figure 1, when the plastic film 1 is bonded to another material with an adhesive or the like, solvents, moisture, etc. permeate through the thickness of the plastic film 1.
This may induce deterioration in the resistance value of the vapor deposited layer 2. Also,
It is also conceivable that the adhesive force at the interface between the plastic surface 1 and the first vapor deposited layer 2 is reduced due to these permeated solvents and the like. FIG. 2 shows one basic configuration for improving these drawbacks, in which second vapor deposited layers 3 are provided on both sides of the first vapor deposited layer 2.

Below, the results of comparison between Examples and Comparative Examples will be described.

Aluminum was deposited on a 75μ polyester film by a conventional method, and chromium was further deposited by a sputter deposition method. And the final surface electrical resistance in this case is 1.1Ω
/It was a mouth. The deposited material was exposed to an atmosphere of 80° C. and 90% RH, and the change in surface resistance value over time was measured.
Even after 01+r, the present invention remained stable, with almost no change in the surface electrical resistance value, proving that it was effective. On the other hand, in the case of using only the first vapor deposited layer of aluminum, which was carried out for comparison, the initial value of 1.1 Ω/hole changed to 200/hole under the same conditions, resulting in a large characteristic deterioration.

[Brief explanation of the drawing]

FIG. 1.2 shows a sectional view of the basic arrangement according to the invention. 1... Plastic film, 2... First vapor deposition layer,
3...Second vapor deposition layer

Claims (1)

[Claims] A first vapor deposited layer of aluminum, zinc, or copper is provided on a plastic film, sheet, or molded article, and a second vapor deposited layer of chromium, nickel, nichrome, stainless steel, Hastelloy alloy, or titanium is provided on the first vapor deposited layer.
An electrode structure characterized in that an electrode is constituted by a conductive layer made of a combination of a second vapor-deposited layer and a second vapor-deposited layer.