JPS58154658A - Method for detecting pin-hole of gold-plated film - Google Patents

Abstract

PURPOSE:To detect the existing number of pin-holes on a prescribed surface area at a glance, by plating Au in prescribed thickness on the surface of Cu, Ni or Ag plating, reacting the Au plating with nitric acid gas and then reaciting the exposed Cu, Ni or Ag with ammonium polysulfide solution to generate a color. CONSTITUTION:When nitric acid 2 is put on the bottom of a case (desiccator) 3 and the case 3 is left as it is for a prescribed period, the inside of the case 3 is filled with nitric acid gas. Subsequently, substances 1 each of which is obtained by plating Au with prescribed thickness on the surface of the Cu, Ni, or Ag plating with prescribed thickness are quickly inserted into the case filled with nitric acid gas, a cover 4 is put on the case and then the case is left as it is under said condition for a prescribed period. After the prescribed period, these substances 1 are taken out from the case 3 and left in the furnace at 120 deg.C for a prescribed time. Filter paper dipped in the ammonium polysulfide solution is attached to the substances 1 to color the substances. Thus the existence of pin-holes on the Au plated film is precisely detected and the existing number of pin-holes on a prescribed surface area can be observed through eyes.

Description

[Detailed Description of the Invention] The present invention relates to a method for detecting pin holes in a gold plating film,
More specifically, a required thickness of gold plating is applied to a required thickness of copper, nickel, or silver plating, and the plated material is reacted with nitric acid gas.

This paper attempts to propose a pinhole detection method characterized by reacting base plating copper, nickel, or silver exposed from the pinhole area with an ammonium polysulfide solution to develop a color.

Conventionally, as a method for detecting pin holes, ■Method of soaking filter paper in coloring liquid and applying it to the plated item.

■The method of magnifying observation using an electron microscope was the main method.

However, in method (■), the coloration is not clear.

The existence of pin holes is not clear.

- The 10,000 method only magnifies a spot with a diameter of 1 m or less, and it takes a long time to confirm how many pin holes are on a given surface area.

The present invention aims to improve the conventional pin hole detection method, and aims to improve the conventional pin hole detection method.
After applying gold plating to the required thickness on the silver plating and exposing it to a container filled with nitric acid gas for a predetermined period of time, the temperature was 120°C.
The present invention proposes a method for detecting pinholes by placing the plated material in a furnace heated to K for a required period of time, and then applying a filter paper soaked in an ammonium polysulfide solution to the surface of the plated material to color it.

The method according to the invention will be explained below with reference to the figures.

The figure shows the process according to the invention.

A desiccator that can be sealed tightly is used for the container (3), and nitric acid (2) is poured into the bottom of the container (3) and left for a required period of time.

After that, the container (3) is filled with nitric acid gas, and the required thickness of copper or nickel is quickly deposited.

Or an article 1 with gold plating of the required thickness on silver plating
11, cover with the lid (4), and leave in the above condition for a predetermined period of time.

After that, the article +11 was taken out from the container (3) and the temperature was 1.
Place in a furnace at 20'0 and leave for the required time.

Next, filter paper soaked in ammonium polysulfide solution is applied to the above article (1) to develop color.

Since this invention is as described above, the presence of pin holes in the gold-plated film is clearly visible.

You can check how many are present on a given surface area.

Next, in order to explain the method of this invention in more detail, [Example] (a) Nitric acid gas exposure: room temperature, 60 minutes (b) Baking in an oven at a temperature of 120±5°C.

30 minutes (c) Immerse the filter paper in the ammonium sulfide solution at room temperature for 5 to 15 seconds (e) Apply the filter paper from item (c) to the surface of the plated product baked in item (b).

(f) The center hole of the pin changes to black (g) Observation (Number of pin-holes/(d)) As described above, if the method of this invention is used, the pin-hole becomes black and can be easily observed. Since it is possible to see at a glance how many pin holes are present in a given surface area, this method is widely recommended as a pin/pole detection method.

[Brief explanation of drawings]

The figure shows the pinhole detection method that is a feature of this invention, in which (1) is an article with gold plating on copper, nickel, or aluminum plating, (2) is with nitric acid, and (4) is with keratin. be. Agent Shin Kuzuno −

Claims (1)

[Claims] On copper, nickel, or silver plating of the required thickness,
After applying gold plating to the required thickness and exposing the plated product to a container filled with nitric acid gas for the required time, the plated product was heated to a temperature of 120°.
C [7J] A gold-plated film in which pinholes are detected by placing it in a heated furnace for the required time, and then applying a filter paper soaked in ammonium polysulfide solution to the surface of the plated material to color it. pinhole detection method.