Electroplating layer stress measurement device

Abstract

The invention relates to an electroplating layer stress measurement device, which consists of an AC excitation power source, an electroplating power source, a measurement sensor, a correction sensor, a cathode piece and a computer. The measurement sensor comprises a magnetic sensing piece C forming a closed magnetic loop, a primary excitation winding N1 and a secondary sensing winding N2 are wound on the magnetic sensing piece C, and insulation paint are coated on the surface of the magnetic sensing piece C except for a plane electroplating area; structure, shape and magnetic property of a magnetic sensing piece C' of the correction sensor are identical to that of the magnetic sensing piece C, the surface is sealed and insulated, primary windings N1 and N1' of the two sensors are connected with the AC excitation power source after being serially connected with each other, and the secondary windings N2 and N2' are respectively connected with amplifiers 1 and 2; and the cathode piece is used for measuring the type of the stress. The device has the advantages of short measurement period, high application measurement precision within the low-stress range and the like; and besides the type of the plating layer stress and the horizontal stress value, the device also can be used for measuring the connection force between the metal plating layer and the base body during the electric crystallization process.

Description

1. Technical field [0001] The invention relates to the measurement of force, especially a device for measuring the internal stress of electroplating layer. 2. Background technology [0002] As we all know, with the emergence of precision electroforming and micro-electroforming technology, many mechanical and mold parts with complex shapes and high precision requirements are made by electroforming. During the electroforming process, the casting coating will generate internal stress. Once the stress is too large, the casting will be deformed and scrapped, causing economic losses to production. The coating stress of castings is closely related to the process conditions of electroplating, and is affected by process parameters such as current density, temperature, metal ions in the bath and the content of various additives, and these parameters will continue to change during the electroforming process. During the casting process, samples are taken from the plating solution in th...

AI Technical Summary

Problems solved by technology

The reason for this shortcoming is mainly that at the initial stage of electroplating, the spiral spring shakes under the agitation of the air pump, and the pointer it drives swings, and the indication is unstable and inaccurate; at the same time, 10-15 minutes after the start of electroplating, due to the small , the deformation force of the spiral spring is small, which cannot effectively eliminate the influence of the static friction of the pointer drive wheel, so that the measured value of the instrument is scattered, sometimes it is zero, and sometimes the fluctuation is several times the steady state value. Generally, it takes 20 minutes to enter a relatively monotonous state. steady state process of change

[0007] The second disadvantage is the low sensitivity and large measurement error in the low stress range

Because the entire surface of the magnetic sensitive part of the sensor (including the hole wall of the magnetic circuit hole) is not insulated, a closed curved surface coating with complex interface shape and continuous shape is formed during electroplating. The stress composition is very complicated, and the type of stress cannot be determined. Whether it is tensile stress or compressive stress, the existing coating stress measurement method cannot be used for quantitative comparison and calibration, and it cannot be connected with the existing coating stress detection specifications

Therefore, it cannot be used for coating stress measurement that meets the testing standards.

Images