RU2341593C1 - Device for crystallisation of leucosapphire melt - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: device for crystallisation of leucosapphire melt contains vacuum chamber, in which thermally are placed: insulated chamber, vacuum pump, connected with vacuum chamber by means of branch pipe, thermal energy source, boat with charge, located on common with thermal energy source axis, vacuum depth sensor, connected with vacuum chamber by means of branch pipe, melt temperature sensor, electric power supply unit, connected with input with electricity network and control unit, which by means of first input is connected with vacuum pump input, and by means of second input - with thermal energy source, introduced into system are: channel of optical connection passing through walls of thermally insulated and vacuum chambers to outer surface of vacuum chamber, and oriented with maximum of diagram of radiation direction at boat content, connected with its output with optical input of melt temperature sensor, electromechanical drive of boat movement, connected with its output with boat, electric magnet, located on the same axis as thermal energy source in thermally insulated chamber and connected galvanically with third output of control unit, first master - master of boat content temperature, first element of comparison, connected by discharge by first inputs with outputs of melt temperature sensor, by second inlets - with first master outputs, by first output - with first controlling input of control unit, time impulse generator, impulse distributor, connected by signal input with impulse generator output, by controlling input - with second output of first element of comparison, and by output - phase-by phase with inputs of electromechanical drive of boat movement, analog-digital converter, connected by its input with output of vacuum depth sensor, second master - master of vacuum depth in vacuum chamber, second element of comparison, connected discharge-by-discharge by first inputs with outputs of second master, and with second inputs - with outputs of vacuum depth sensor in vacuum chamber, and OR element, connected by first input with output of second element of comparison, by second input - with first output of first element of comparison, and by output - with second controlling input of control unit, control unit being connected by power inputs with outputs of power supply unit, by first output - with input of vacuum pump, with second output - with input of thermal energy source, sensor of vacuum depth in vacuum chamber is made on inverse-magnetron vacuum-meter, sensor of melt temperature - on multi-channel and radiation pyrometer, and electromechanical drive of boat movement - on step engine.

EFFECT: improvement of properties of leucosapphire crystals (dielectric inductivity up to ε = 5,63, against ε = 5,87 and flintiness up to N = 9,23, against 8,96), extension of technological parameter ranges, temperature and depth of vacuum, higher accuracy of technological process of leucosapphire crystal growing with simultaneous minimization of time and energy consumption.

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Description

The crystallization unit of a leucosapphire melt refers to automatic technological means, and in particular, to means of directed crystallization of binary compounds, including leucosapphire, in the technology of micro- and nanoelectronic equipment.

A known installation for growing single crystals from a melt containing a crystallization (vacuum) chamber, a heater installed therein, a heater voltage control system, a crystallization chamber vacuum system with a control unit and a water cooling system, temperature and water flow control units in the cooling system, outputs of control units a vacuum system and water temperature control and one of the outputs of the water flow control unit is connected to the corresponding inputs of the control system on voltage of the heater, the other output of the water flow unit is connected to the input of the control unit of the vacuum system, and the water cooling system is made in the form of independently adjustable cooling loops of the crystallization chamber, the vacuum system and the voltage control system of the heater, and each circuit is equipped with temperature and water flow control units [1 ]. Italicized features common to the subject of the invention.

The disadvantages of the known installation for growing single crystals from a melt are the limited ability to control the direction of crystallization, as well as the accuracy and reliability of the control results of technological parameters, vacuum depth and temperature, and control, which is due to the capabilities of the used sensors of technological parameters

Known as being closer in technical essence to the invention, a plant for the crystallization of binary compounds (including leucosapphire melt), including a vacuum chamber in which a thermally insulated chamber is placed, a vacuum pump connected by a nozzle to a vacuum chamber, a heat source, a boat with a charge placed on a common axis with a source of thermal energy, an electrical power unit connected to the input by an electric network, and a control unit, as well as sensors with indicators of melt temperature and depth mind in the cell [2]. Italicized features common to the subject of the invention.

The disadvantages of the known installation for crystallization of binary compounds are the limited ability to control the direction of crystallization, as well as the accuracy and reliability of the results of the control of technological parameters, vacuum depth and temperature, and control, which is due to the capabilities of the used sensors of technological parameters

The objective of the invention is to improve the properties of leucosapphire due to directional crystallization, as well as improving the accuracy and performance of process equipment and minimizing time and energy costs.

The technical result consists in directed crystallization of leucosapphire, as well as in the exclusion of the human operator from the control loop, in automatic, instrumental, control of technological parameters, vacuum depth and the temperature of the melt of leucosapphire, which reduces the dielectric constant and increases the hardness of leucosapphire, and also increases the accuracy and reliability the results of the control of technological parameters, and in the automatic control of the source of thermal energy and the drive for moving the boat, which leads to m minimizing the time and energy consumption for the process.

The technical result is ensured by the fact that in the crystallization unit of a leucosapphire melt containing a vacuum chamber in which a thermally insulated chamber is placed, a vacuum pump connected by a nozzle to a vacuum chamber, a heat source, a boat with a charge placed on a common axis with a heat source, an electric unit a power supply connected to the power input with an electric network, and a control unit, as well as a vacuum depth sensor, connected by a nozzle to a vacuum chamber, a melt temperature sensor and ind cathodes of vacuum depth in the vacuum chamber and melt temperature, connected by inputs to the outputs of the sensors of the vacuum depth and temperature of the contents of the boat, respectively, introduced an optical communication channel passing through the walls of the insulated chamber and the vacuum chamber to the outer surface of the vacuum chamber and oriented by the maximum radiation pattern of the entrance to the contents of the boat , the temperature sensor is connected by an optical input to the output of the optical communication channel, the electromechanical drive for moving the boat is connected mechanically connected to the output by a boat, an electromagnet located on a common axis with a source of thermal energy in a vacuum chamber and galvanically connected to the third output of the control unit, a first control unit, a temperature control unit for the contents of the boat, a first comparison element connected bitwise by the first inputs to the outputs of the melt temperature sensor, the second inputs - with the outputs of the first master, and the first output - with the first control input of the control unit, a clock pulse generator, a pulse distributor, connected to the input with the output of the pulse generator, the control input with the second output of the first comparison element, and the output in phases with the inputs of the electromechanical drive for moving the boat, an analog-to-digital converter connected to the input with the output of the vacuum depth sensor, a second master, a vacuum depth gauge in the vacuum chamber , a second comparison element connected bitwise by the first inputs to the outputs of the second setter, and the second inputs to the outputs of the vacuum depth sensor in the vacuum chamber, and the OR element connected the first input with the output of the second comparison element, the second input with the first output of the first comparison element, and the output with the second control input of the control unit, and the control unit is connected by power inputs to the outputs of the power supply, the first output with the input of the vacuum pump, and the second output with the input of the heat energy source, the vacuum depth sensor in the vacuum chamber is made on an inverse magnetron vacuum gauge (with a measured pressure limit of 10 ^-14 mm Hg), the melt temperature sensor is made on a multichannel a radiation pyrometer (with a limit of measured temperatures up to 10 ¹⁵ K), and an electromechanical drive for moving the boat - on a stepper motor (with discretization of movements up to 10 ^-4 mm).

The functional diagram of the installation of crystallization of melt leucosapphire is shown in the drawing.

The installation of a leucosapphire melt contains a vacuum chamber 1, a heat-insulated chamber 2 located in the vacuum chamber 1, a vacuum pump 3 connected by a nozzle 4 to a vacuum chamber 1, a first sensor 5, a vacuum depth sensor connected by a nozzle 4 to a vacuum chamber 1, a heat source 6 and an electromagnet 7 located on a common axis in a heat-insulated chamber 2, a boat 8 with a charge or a leucosapphire melt 9, placed in a heat-insulated chamber 2, on a common axis with a source of thermal energy 6 and an electromagnet 7, block 10 power supply, connected by an input to a general-purpose electrical network, a control unit 11 connected by power inputs to the outputs of a power supply unit 10, a first output (a) with an input of a vacuum pump 3, a second output (b) with a heat source 6, and a third output ( c) with an electromagnet 7, an optical communication channel 12 passing through the walls of a thermally insulated chamber 2 and a vacuum chamber 1 to its outer surface and oriented by the maximum radiation pattern to the contents of boat 8, a second sensor 13, a temperature sensor with of a held boat, connected by an optical input to the output of the optical communication channel 12, the first setter 14, the setpoint temperature control of the boat 8, the first comparison element 15 connected bitwise by the first inputs to the outputs of the first setter 14, the second inputs to the outputs of the boat content temperature sensor 13, and the first output is with the first control input of the control unit 11, a clock pulse generator 16, a pulse distributor 17 connected by a first signal input to the output of the pulse generator 16, and a second input, an input board, with the second output of the first comparison element 15, an electromechanical drive 18 for moving the boat 8, connected by inputs, electrically, in phase with the outputs of the pulse distributor 17, and an output, mechanically, with boat 8, an analog-to-digital converter 19, connected by an input to the output of the first 5, a second setter 20, a vacuum depth gauge in the vacuum chamber 1, a second comparison element 21 connected bitwise with the first inputs to the outputs of the second setter 20, and the second inputs with the outputs of the vacuum depth gauge 5 the second chamber, and the OR element 22 connected by the first input to the first output of the first comparison element 15, the second input to the output of the second comparison element 21, and the output to the second control input of the control unit 11, and the vacuum depth sensor 5 is made on an inverse-magnetron a vacuum gauge, the temperature gauge 13 for the contents of the boat is made on a multi-channel radiation pyrometer, and the electromechanical drive 18 for moving the boat is made on a stepper motor.

Installation crystallization melt leucosapphire works as follows.

The setters 20 and 14 set the set values of the vacuum depth N ₂₀ ≡ P _s in the chamber 1 and the temperature N ₁₄ ≡ T _{s of the} contents of the boat 8, respectively (here the sign ≡ is the proportional sign). The leucosapphire charge 9 is loaded into boat 8, and boat 8 is placed in the starting position in the heat-insulated chamber 2, on the axis common to the heat energy source 6 and electromagnet 7. After closing the locks of the heat-insulated 2 and vacuum 1 chambers, the unit starts up (power supply lock circuits installation in figure 1 is not shown). Content output setting devices 14 (N ≡T _{14 h)} and 20 (N ₂₀ ≡P _h) compared with the contents of the sensor output 13 (N ₁₃ ≡T (t)) and an analog-digital converter 19 (N ₁₉ ≡P (t)) respectively. Under the condition N ₁₉ <N ₂₀ , according to the start signal, power is supplied to the power input of the vacuum pump 3, through the control unit 11, from its corresponding output. The vacuum pump 3 lowers the pressure in the vacuum chamber 1. The pressure in the vacuum chamber 1 is constantly monitored, in real time, by the vacuum depth sensor 5. The vacuum depth sensor 5 is capable of evaluating the pressure P (t) over an interval of up to 10 ⁻¹⁴ mm Hg. The analog value of the vacuum depth P (t) in the chamber 1 is converted by an analog-to-digital converter 19 into its digital value N ₁₉ ≡ P (t). Comparison element 21 at its output generates a high potential at P (t) ≤P _s , at N ₁₉ ≤N ₂₀ , and a low potential at P> P _s , N ₁₉ > N ₂₀ , which ensures the pump operates until the condition P (t ) = P _s and excludes its operation at P (t)> P _s . The temperature sensor 13 continuously measures the temperature T (t) of the contents of the boat 8. The temperature sensor 13 provides a measurement of the temperature of the contents of the boat 8 by T (t) = q | (I _{λ1T (t)} -I _{λ2T (t)} ) / (λ ₁ -λ ₂ ) |, up to T = 10 ¹⁵ ° С with an accuracy of at least ± 20 ° С, where: q is the proportionality coefficient, λ ₁ and λ ₂ are the wavelength of the radiation recorded by the pyrometer, and I _{λ1T (t)} and I _{λ2T (t )} are the radiation intensities at wavelengths λ ₁ and λ _2, respectively, at an arbitrary temperature T (t) of the radiating surface. The inertia of the sensor 13 does not exceed 0.001 seconds. The contents of the outputs of the sensor 13 (N ₁₃ ≡T _z ) and the setter 14 (N ₁₄ ≡T (t)) are continuously compared by the comparison element 15. For N ₁₃ <N ₁₄ (for T (t) <T _s ), but for N ₁₉ ≤N ₂₀ (for P (t) ≤ P _s ), a high potential is generated at the output of element 22 OR, and the control unit 11 the output is connected to the corresponding output of the power supply unit 10 with a heat energy source 6, the contents of the boat are heated, its temperature T (t) rises. Upon reaching the equality N ₁₃ = N ₁₄ (T (t) = T _h ) at the second output of the comparison element 15, a high potential is established, on the leading edge of which the control unit 11 and the pulse distributor 17 are activated, while the power is supplied to the winding of the electromagnet 7, under the action of a direct current flowing in the winding, the electromagnet 7 generates a constant magnetic field of strength H≈30 ÷ 40 kA / m (H≈400 ÷ 600 Oe) in the direction of its axis, and to the input of the boat moving drive 18, the boat moving drive 18 moves step by step boat 8 along the common axis source 6 of thermal energy and an electromagnet 7. Drive 18 moving the boat, step by step with a frequency f ₁₆ determined by the generator 16, moves the boat 8 until the inequality N ₁₃ <N ₁₄ (T (t) <T _s ), and when equality N ₁₃ = N ₁₄ (T (t) = T _h ) the boat moving drive 18 again moves the boat 8 along the common axis of the heat source 6 and electromagnet 7. And so until the boat reaches its finish point 8, after which the vacuum pump 3, source 6 thermal energy, an electromagnet 7 and a drive 18 for moving the boat 8, through the distributor 17, elem The OR 22 and the control unit 11, respectively, are de-energized, and the crystal 9 after cooling can be removed from the installation.

The following comparative results of the properties of leucosapphire were experimentally established: during spontaneous crystallization, N = 8.96 and ε = 5.87; with directed crystallization, N = 9.23 and ε = 5.63; other properties of leucosapphire have not been investigated.

Thus, the installation of crystallization of a leucosapphire melt provides an improvement in the properties (dielectric constant and hardness) of leucosapphire crystals, as well as expanding the ranges of technological parameters, temperature and vacuum depth, process, accuracy of maintaining the technological process of growing leucosapphire crystals while minimizing time and energy costs.

Information sources

1. Patent RU 2085625, C30V 11/00, 07.27.1997.

2. Patent FR 1494831, B01J // H01I, 09.15.1967.

Claims (1)

An apparatus for crystallization of a leucosapphire melt containing a vacuum chamber in which a thermally insulated chamber is placed, a vacuum pump connected by a nozzle to a vacuum chamber, a heat source, a boat with a charge placed on a common axis with a thermal energy source, a vacuum depth gauge connected by a nozzle to a vacuum chamber , a melt temperature sensor, an electrical power unit connected to the input by an electric network, and a control unit, characterized in that the last first output is connected to an input of a smart pump, the second output is with a heat source, and an optical communication channel is introduced into the installation, passing through the walls of the insulated and vacuum chambers to the outer surface of the vacuum chamber, oriented by the maximum radiation pattern to the contents of the boat and connected by the output to the optical input of the melt temperature sensor , an electromechanical drive for moving the boat, connected by the exit to the boat, an electromagnet located on the same axis as the heat source in the heat a galvanized chamber and galvanically connected to the third output of the control unit, the first control unit is a temperature controller for the contents of the boat, the first comparison element connected bitwise with the first inputs with the outputs of the melt temperature sensor, the second inputs with the outputs of the first unit, and the first output with the first control input of the unit control, clock generator, pulse distributor connected by a signal input to the output of the pulse generator, control input - with the second output of the first element the output, in phase with the inputs of the electromechanical drive for moving the boat, an analog-to-digital converter connected to the input with the output of the vacuum depth gauge, the second master is the vacuum depth gauge in the vacuum chamber, the second comparison element connected bitwise by the first inputs to the outputs of the second master, and the second inputs - with the outputs of the vacuum depth sensor in the vacuum chamber, and the OR element connected by the first input to the output of the second comparison element, the second input with the first output of the first comparison element the output is connected to the second control input of the control unit, the control unit being connected to the power inputs with the outputs of the power supply unit, the first output to the input of the vacuum pump, and the second output to the input of the heat energy source, the vacuum depth sensor in the vacuum chamber is inverted a magnetron vacuum gauge, a melt temperature sensor on a multi-channel radiation pyrometer, and an electromechanically driven boat movement drive on a stepper motor.