RU-2861493-C2 - METHOD FOR SOLDERING SPUTTERING TARGET MADE OF SPUTTERABLE MATERIAL TO HEAT SINK BASE

RU2861493C2RU 2861493 C2RU2861493 C2RU 2861493C2RU-2861493-C2

Abstract

FIELD: materials science. SUBSTANCE: invention relates to a method for manufacturing a sputtering target used as a cathode on a heat sink base. The surface of the sputtering target is preliminarily subjected to two-layer metallisation by applying a chromium film and a copper film over it using vacuum evaporation. Then, tinning the surface of the sputtering target subjected to two-layer metallisation and the heat sink base with a fusible solder at a temperature of 1.1-1.2 times the liquidus temperature of the fusible solder. Then, placing the target on the heat sink base, mating their soldered surfaces, wherein the heat sink base is rigidly fixed on a steel plate. Performing soldering in a vacuum furnace at a temperature of 1.1-1.2 times the liquidus temperature of the solder and a vacuum of less than 0.1 Pa with a hold of at least 10 minutes. EFFECT: obtaining a soldered joint between the target material and the copper heat sink base. 2 cl, 1 dwg, 1 ex

Inventors

Budnev Aleksandr Iurevich
Prosovskii Oleg Fedorovich
Isamov Andrei Nizametdinovich
Prosovskii Iurii Olegovich
Petrachkov Dmitrii Nikolaevich

Dates

Publication Date: 20260505
Application Date: 20240919

Claims (2)

1. A method for manufacturing a sputtering target used as a cathode on a heat-sinking base, characterized in that the surface of the sputtering target is preliminarily subjected to a two-layer metallization by applying a chromium film and a copper film on top of it by vacuum evaporation, then tinning is carried out on the surface of the sputtering target subjected to the two-layer metallization and the heat-sinking base with a low-melting solder at a temperature of 1.1-1.2 times the liquidus temperature of the low-melting solder, after which the target is placed on the heat-sinking base with the mating of their soldered surfaces, wherein the heat-sinking base is rigidly fixed on a steel plate, after which soldering is carried out in a vacuum furnace at a temperature of 1.1-1.2 times the liquidus temperature of the solder and a vacuum of less than 0.1 Pa with a holding time of at least 10 minutes.
2. The method according to paragraph 1, characterized in that tin, lead, bismuth, indium and their alloys are used as the low-melting solder.

Description

The invention relates to soldering and can be used to manufacture a composite target from refractory, difficult to deform and brittle materials used for vacuum deposition of thin-film coatings. A method is known for soldering metals, primarily aircraft parts made of titanium and its alloys, with preliminary metallization of the surfaces to be joined, in which the parts are placed in a heating medium, characterized in that, in order to improve the quality of the connection, ultrasonic vibrations are introduced into the heating medium (A.s. No. 211289, IPC B23K 1/06, application No. 1096933/27 dated 12.08.1966, published 20.02.2006). A disadvantage is that when soldering the material to the target base, ultrasonic vibrations do not prevent the formation of air pockets in the soldering medium, which can lead to gassing during the sputtering process and deteriorate the structural strength. The properties of the metallized layer described above do not always allow for bonding non-metallic materials to the base. A method is known based on the preparation (cleaning) of contact surfaces and their connection by soldering (patent RU No. 2104130, IPC B23K 1/00, dated 10.02.2006). Soldering is performed with amorphous solder. The components to be soldered are heated to a temperature of 0.4-0.6 times the solder liquidus temperature. An initial isothermal hold is performed for 20-30 min. The components to be soldered are heated to a temperature of 1.1-1.2 times the solder liquidus temperature, a second isothermal hold is performed for 5.0-2.0 min, and then cooled in two stages. Soldering is performed with copper-nickel-phosphorus alloy powder of 20-100 μm fraction from a tape 30-50 μm thick. The disadvantage is that the lack of preliminary surface metallization does not ensure the necessary adhesion when soldering dielectrics; soldering in an atmospheric environment can also lead to gassing during the spraying process and deterioration of the structural strength. The closest to the claimed invention is a method for soldering difficult-to-solder materials, which consists of preparing (cleaning) the surface of the materials for subsequent soldering (Russian Federation application No. 93009686 dated February 24, 1993, IPC B23K 1/20, published February 10, 1998). The elements to be soldered are tinned with low-melting eutectic alloys of bismuth, indium, tin, cadmium, lead, and gallium in air at a temperature of up to 60°C and maintained at the same temperature for 0.5-1.5 hours. After such tinning, soldering with metal-ceramic (diffusion-hardening) or soft (lead-tin) solders becomes possible. The method does not always provide the required adhesion of surfaces due to the absence of intermediate adhesive layers and allows the formation of air cavities in the thickness of the solder, which can lead to insufficient contact of the surfaces, deformation, cracking and destruction of the target material, which is especially important when soldering composite and oxide ceramic cathodes. The technical result of the invention is the production of a soldered joint between the target material and a heat-dissipating copper base. The technical result is achieved by providing a method for manufacturing a sputtering target used as a cathode on a heat-dissipating base, characterized in that the surface of the sputtering target is preliminarily subjected to a two-layer metallization by applying a chromium film and a copper film on top of it by vacuum evaporation, then tinning is carried out on the surface of the sputtering target subjected to the two-layer metallization and the heat-dissipating base at a temperature of 1.1-1.2 times the liquidus temperature of the low-melting solder, after which the target is placed on the heat-dissipating base with the mating of their soldered surfaces, wherein the heat-dissipating base is rigidly fixed on a steel plate, after which soldering is carried out in a vacuum furnace at a temperature of 1.1-1.2 times the liquidus temperature of the solder and a vacuum of less than 0.1 Pa with a holding time of at least 10 minutes. Tin, lead, bismuth, indium and their alloys are used as low-melting solder. Target surface preparation involves vacuum deposition (evaporation) of a chromium (Cr) film 2-5 µm thick, followed by a second layer of copper (Cu) 2-5 µm thick. Due to the physical and chemical properties of chromium films, they exhibit high adhesion to the surfaces of many materials. The copper layer ensures high-quality tinning with solders. The target surface of the sputtered material prepared in this manner is tinned with the selected solder at a temperature of 1.1 - 1.2 times the solder's liquidus temperature, then slowly cooled to prevent damage or warping of the material. Depending on the application conditions, solders such as tin, lead, bismuth, indium, and their alloys are used. Preparing the base: To prevent the copper heat-conducting base of the target from warping due to the heat generated during sol