SU712230A1 - Electrolyte for electrochemical etching of pin contacts - Google Patents

Description

one

The invention relates to electrochemical and electrolysis processing methods and, in particular, relates to the technology of manufacturing metal tips, used as autoemitters and other contacting elements in crystal detectors, etc.

Known and used for electrochemical baiting and refractory wires: metal electrolytes based on an aqueous 25% solution of sodium hydroxide with the addition of 0.01% solution of copper 1.

However, when using solutions of caustic potash or caustic soda as electrolyte, the length of the cone part of the tips varies considerably, and a number of special devices are used to reduce the length of the cone part of the tips, which significantly complicate the process of their manufacture.

The aim of the invention is to achieve the radius of the tip and to ensure the formation of the optimum length of the cone.

For this, thiourea is additionally introduced into the known solution and

1triethanolamine in the following ratio of components, wt.%:

Caustic soda 15,0-20,0

Thiourea 0.5-1.5

Triethanolamine2.0-3.0

These components allow the process to be stabilized by changing the surface tension of the solution and reducing gassing.

0

Three solutions are prepared to obtain tips with an optimal ratio of the radius of the apex and the length of the cone. A voltage of 7.5 V with a frequency of 50 Hz is applied to the electrodes (the wire blank is immersed in the electrolyte per μm) for 1–3 s (until the reaction ceases). Then the end of the wire is again immersed in the electrolyte (..20 microns) and

0 serves 1-3 with the same voltage.

Example 1. In an electrolyte containing, g / l:

Caustic soda 150

Thiourea5

Triethanolamine 20

five

at a temperature of 20 ± 5 ° C, a voltage of 7.5 V, a frequency of 50 Hz, spikes are obtained, the radius of which is l. 1 micron and conical length 64 microns.

Claims (3)

0 Example 2. In the electrolyte, which is given, g / l: Caustic soda 175 Thiourea 10 Triethanolamine 25 at 20 + 5 ° C, voltage 7.5 V and frequency 50 Hz receive points, the radius of the tip of which is 1 µm and the length of the conical part 60 1 km. Example 3. In an electrolyte containing, g / l: Caustic soda 200 Thiourea15 Triethanolamine30 at 20 + 5 ° C, voltage 7.5 Hz, sharp points are obtained, the radius of curvature of which is 1 µm, 55 µm on the conical part. The data show that, obtained using a caustic soda solution with the addition of thiourea and triethanolamine, have a stable geometric dimensions, namely; the length of the conical part is equal to 60 ± 5 µm with a radius of the tip of the tip of 1 µm. This provides a sufficiently high mechanical strength of the needle contacts; which allows them to be used for repeated contacting without blunting their needles. The manufacture of needle contacts in the proposed electrolyte provides a high reproducibility of the geometric dimensions and shapes of the tips. The electrolyte allows the process to be carried out without the use of special tools and toxic materials. Electrolyte for electrochemical etching of needle contacts made of water-based refractory materials, alkali and thiourea, in that, in order to improve processing accuracy, it additionally contains Triethanolamine in the following ratio of components, weight,%: Alkali15,0- 20.0 Thiourea 0.5-1.5 Triethanolamine 2.0-3.0 Water Remaining Sources of information taken into account during the examination 1. Coel D. Crystal detectors. M., Sov, Radio, 1950, pp. 155-256.