Evaporation unit

Abstract

This disclosure relates to an evaporation unit (10) for evaporating a metal evaporation material, comprising: - an evaporation crucible (40) inside an evaporation chamber (50); - a melting crucible (20) located outside the evaporation chamber (50) and fluidly coupled to the evaporation crucible (40), the melting crucible (20) including a melting cavity (23) for melting the metal evaporation material, for housing the molten evaporation material (12), and / or for heating the molten evaporation material (12); and - a measuring arrangement (80) coupled to the melting crucible (20) and operable to quantitatively measure at least one of the filling level (28) of the molten evaporation material (12) in the melting cavity (23) and the mass of the molten evaporation material (12) in the melting crucible (20), the measuring unit (80) further operable to generate a measuring signal indicating at least one of the filling level (28) and mass of the molten evaporation material (12); The present invention relates to an evaporation unit (10) including a controller (90) connected to a measuring arrangement (80) and operable to derive a filling level (48) of molten evaporation material (12) inside an evaporation crucible (40) based on a measurement signal received from the measuring arrangement (80).

Description

Technical Field

[0001] The present invention relates to the field of coating substrates, and more particularly, to the field of coating metal substrates with a metal coating or a corrosion protection coating. In a further aspect, the present invention relates to an evaporation unit, a coating arrangement, and a method for determining the filling level of a molten evaporation material inside an evaporator.

Background Art

[0002] Coating materials such as gaseous metals or metal layers can be coated on the surface of a metal substrate such as a single sheet or strip steel. Here, the substrate is placed in a coating or vacuum atmosphere. In vacuum deposition, various deposition methods can be applied, whereby a solid or liquid coating material, such as a metal coating material, is evaporated. This typically means heating the evaporation material to the evaporation temperature, for example, in a vacuum atmosphere, to cause it to transition to a gaseous or vapor state. After the evaporation material has evaporated sufficiently, a thin film is formed as a coating on the substrate.

[0003] Typically, in the case of physical vapor deposition (PVD) of fairly large substrates, it is very difficult to control the deposition rate of an evaporator located inside a vacuum atmosphere. Furthermore, it is very difficult to provide a sufficient and / or constant supply of molten evaporation material to the evaporator and thus into the evaporation chamber.

[0004] For example, Patent Document 1 discloses an operating arrangement including first and second crucibles fluidly connected. The first crucible can be placed inside a vacuum chamber, and the second crucible can be placed outside the vacuum chamber. With this evaporation arrangement, the filling level of the first crucible is controlled by controlling the gas pressure inside the second crucible.

[0005] Modifying the gas pressure in a second crucible outside the vacuum chamber, or modifying the gas pressure using the second crucible, is extremely difficult and requires precise installation and control of each piece of equipment to provide sufficient and accurate fluid level control. In addition, the requirement to modify the gas pressure in the second crucible hinders the supply of additional material or evaporating material into the crucible without interrupting the coating process. [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] EP3812481A1 [Overview of the project] [Problems that the invention aims to solve]

[0007] Therefore, it is desirable to provide improvements to evaporation units for evaporating metallic evaporation or coating materials, such improvements that provide fairly easy and straightforward control of the filling level of the molten evaporation material inside the evaporation crucible located inside the evaporation chamber. It is also desirable to enable and / or provide a fairly easy and straightforward method for supplying the evaporation or coating material to each crucible.

[0008] Precisely controlling the filling level of the liquid molten vaporizing material in the evaporation crucible or evaporator inside the vacuum chamber is also extremely difficult and a demanding requirement. The temperature inside the vacuum chamber can exceed 500°C, making it difficult to have electrically or electronically operated sensors inside the vacuum chamber.

[0009] Furthermore, transmitting electrical signals from inside the vacuum chamber to a controller located outside the vacuum chamber is extremely difficult and presents stringent requirements. Additionally, a fill level sensor located inside the vacuum chamber may be subjected to continuous accumulation of evaporating material during use of the evaporation unit. To that extent, sensors or sensing arrangements inside the evaporation chamber for determining or measuring the fill level of molten material in the evaporator may require periodic maintenance or may exhibit only a limited lifespan.

[0010] Therefore, it is desirable to provide an improved evaporation unit that enables precise measurement or determination of the filling level of the evaporating material inside the evaporation crucible without using measuring instruments inside the evaporation chamber. [Means for solving the problem]

[0011] The problems and defects described above are resolved by the configuration of the evaporation unit, the covering arrangement, and the method for deriving or determining the filling level of the molten evaporation material according to the independent claims. Numerous examples and embodiments are the subject matter of their respective dependent claims.

[0012] In one embodiment, the disclosure relates to an evaporation unit for evaporating a metallic evaporation material. The evaporation unit includes an evaporation crucible inside an evaporation chamber. The evaporation unit further includes a molten crucible outside the evaporation chamber. The molten crucible and the evaporation crucible are fluidically connected to each other. The molten crucible includes a molten cavity for melting the metallic evaporation material, for making the metallic evaporation material, and / or for heating the evaporation material. In some examples, the evaporation crucible contains the molten evaporation material. The molten evaporation material can be supplied from the outside, for example, by a separate melting unit into the molten cavity, or the evaporation material can be solid, for example, granular, and supplied into the molten cavity. For example, the metallic evaporation material is melted inside the molten cavity. The molten crucible and the evaporation crucible are fluidically connected. Thus, the molten evaporation material can flow from the molten crucible to the evaporation crucible and into the evaporation crucible via this fluid connection.

[0013] Typically, the fluid connection between the melting crucible and the evaporating crucible is a free-flowing fluid connection, easily linking the melting crucible to the evaporating crucible. This fluid connection allows the fluid level in the evaporating crucible to conform to a complementary or corresponding fluid level in the melting crucible, and vice versa.

[0014] The evaporation unit further includes a measuring arrangement, which is coupled to a molten crucible. The measuring arrangement is operable to quantitatively measure at least one of the packing level of the molten evaporation material in the molten cavity and at least one of the mass of the molten evaporation material in the molten cavity or molten crucible. The measuring unit is further operable to generate a measuring signal indicating at least one of the packing level and mass of the molten evaporation material in the molten cavity or molten crucible.

[0015] The evaporation unit further includes a controller that is connected to a measurement setup and is operable to derive the level of molten evaporation material inside the evaporation crucible based on measurement signals received from the measurement setup.

[0016] In other words, the fluid connection between the evaporation crucible and the melting crucible allows the packing level of the molten vapor material inside the evaporation crucible to be measured or derived indirectly, by quantitatively measuring at least one of the packing level of the molten vapor material in the molten cavity and the mass of the molten vapor material in the melting crucible.

[0017] When the mass or weight of the molten vaporizing material in a melting crucible is measured, and the geometry of the molten cavity is generally known, the packing level of the molten vaporizing material in the molten cavity can be derived from the measured mass by further taking into account the temperature of the molten vaporizing material and the density of the molten vaporizing material at a given or measured temperature. By deriving the packing level of the molten vaporizing material in the evaporation crucible through quantitative measurement of the packing level or mass of the molten vaporizing material in the molten cavity, it is possible to substantially avoid installing or using rather complex or sensitive sensors or detectors inside the evaporation chamber, which may be contaminated during use of the evaporation unit.

[0018] In addition, quantitatively measuring at least one of the mass and packing level of the molten vaporized material inside the melting crucible becomes considerably easier to achieve by using relatively simple sensors, sensor elements, or measuring devices. Quantitative measurement of at least one of the packing level and mass of the molten vaporized material outside the vacuum chamber provides a fairly immutable or permanent, and therefore fairly precise, determination of the packing level of the molten material inside the melting crucible and the vaporizing crucible.

[0019] In this way, fairly precise and continuous monitoring of the filling levels of the melting and evaporating crucibles can be provided, which enables fairly precise and immediate control of the entire evaporation or coating process.

[0020] In further examples, the measurement configuration includes at least one of a pressure sensor and a temperature sensor. The pressure sensor is operable to measure at least one of the ambient pressure inside the molten cavity and the vacuum pressure inside the evaporation chamber. The temperature sensor is operable to measure the temperature of the molten evaporation material inside at least one of the molten cavity and the evaporation crucible. In some examples, the evaporation unit includes two pressure sensors, one of which is located inside the evaporation chamber and operable to measure the vacuum pressure inside the evaporation chamber. A further pressure sensor is typically located outside the evaporation chamber. The further pressure sensor may be operable to measure atmospheric pressure or ambient pressure in the environment of the molten crucible.

[0021] As an addition or alternative, the vacuum pressure inside the evaporation chamber can also be obtained from a vacuum pump coupled to the evaporation chamber, which is operable to establish various low-pressure or vacuum conditions inside the evaporation chamber. To that extent, each pressure sensor operable to provide the vacuum pressure inside the evaporation chamber may be located outside the evaporation chamber, but may also be in gas flow communication with the inside of the evaporation chamber.

[0022] In some examples, the evaporation unit may also be equipped with at least two temperature sensors, the first of which may be operable to measure the temperature of the molten evaporating material inside the molten crucible or molten cavity. Furthermore, the second temperature sensor may therefore be operable to measure the temperature of the molten evaporating material inside the evaporation crucible or evaporator.

[0023] By measuring at least one of the ambient pressure and vacuum pressure, the pressure difference between the molten crucible and the evaporative crucible can be derived, which is further taken into account by a controller for deriving the packing level of the molten evaporative material inside the evaporative crucible. Similarly, the temperature of the molten evaporative material inside the molten crucible and / or inside the evaporative crucible can also be taken into account.

[0024] Based on knowledge of the pressure difference between the environment of the evaporation crucible and the environment of the melting crucible, it becomes possible to accurately determine or accurately derive the filling level of the molten evaporation material inside the evaporation crucible based on at least one of the filling level of the molten evaporation material in the melting cavity and the mass of the molten evaporation material in the melting crucible.

[0025] In a further example, the controller of the evaporation unit is operable to derive the filling level of the molten evaporation material inside the evaporation crucible by further considering at least one of the ambient pressure inside or around the melting cavity, the vacuum pressure inside the evaporation chamber, the temperature of the molten evaporation material inside the cavity, and the temperature of the molten evaporation material inside the evaporation crucible.

[0026] In a further example, it is also conceivable to measure the temperature of the molten evaporation material inside a fluid connection, for example inside a fluid pipe extending between the evaporation crucible and the melting crucible and fluidly connected to the evaporation crucible and the melting crucible, or along that fluid connection.

[0027] Furthermore, by taking into account the temperature of the molten evaporation material, the temperature dependence of the density of the evaporation material can be precisely taken into account, and based on the measured mass of the evaporation material, the filling level of the molten evaporation material inside the melting crucible and / or inside the evaporation crucible can be determined.

[0028] Due to the fluid connection between the melting crucible and the evaporation crucible, the filling levels of the molten evaporation material inside the melting crucible and inside the evaporation crucible are subject to a common hydrostatic pressure. The hydrostatic pressure p is defined as p = ρgh, which is the product of the gravitational constant g, the density ρ of the material, and the height of the fluid level of the evaporation material inside each crucible.

[0029] If the molten crucible and the evaporation crucible are subjected to different ambient pressures, the pressure difference between them will result in corresponding modifications to the packing levels of the molten and evaporated material within each crucible. Furthermore, if, for example, the molten crucible is exposed to atmospheric pressure, the effect of atmospheric pressure must also be considered when calculating the hydrostatic pressure of the molten crucible.

[0030] Assuming that the evaporation crucible and the melting crucible are exposed to the same ambient pressure and are positioned at a common level, the height of the filling level of the molten vapor material in the evaporation crucible should be the same as the respective filling levels of the vapor material in the melting crucible. Now, if the evaporation crucible is placed inside the evaporation chamber and the evaporation chamber is evacuated, the pressure near the evaporation crucible will decrease, which will result in an increase in the filling level of the molten vapor material in the evaporation crucible. The difference in ambient or surrounding pressure between the evaporation crucible and the melting crucible can be easily compensated for by positioning the evaporation crucible at a higher level than the melting crucible. This makes it possible to draw the molten vapor material vertically from the melting crucible by suction, and therefore against the action of gravity.

[0031] The difference in height between the molten crucible and the evaporation crucible can be compensated for by the difference in ambient pressure between the evaporation crucible and the molten crucible.

[0032] Typically, in some examples, the position of the evaporation crucible inside the evaporation chamber is fixed. The position of the evaporation crucible inside the evaporation chamber is fixed at least vertically.

[0033] In a further example, the evaporation unit includes a liquid level regulator coupled to the molten crucible, which is operable to vary the level of the molten evaporation material inside the molten cavity relative to the ground and / or the sidewall of the molten crucible or molten cavity. By varying the absolute liquid level of the molten evaporation material relative to the ground and / or the sidewall of the molten crucible, the liquid level of the molten evaporation material inside the evaporation crucible can also be changed and corrected accordingly. An increase in the liquid level of the molten material in the molten crucible is equally transmitted to each correction of the liquid level of the molten evaporation material in the evaporation crucible.

[0034] Furthermore, the controller can also take into account the temperature dependence of the density of the molten vaporized material, for example, when the temperature of the molten vaporized material in the vaporization crucible is higher than the temperature of the molten vaporized material in the vaporization crucible.

[0035] Typically, a liquid level regulator provides direct and absolute correction or adjustment of the liquid level of the molten vaporizing material inside the molten cavity, which is then equally reflected in the respective correction of the liquid level of the molten vaporizing material inside the evaporation crucible through fluid connection with the evaporation crucible.

[0036] In a further example, the filling level of the molten vapor material inside the molten crucible can be adjusted by varying the level or height of the molten vapor material inside the molten crucible. Thus, the liquid level of the molten vapor material inside the molten crucible can be varied relative to the molten crucible or its sidewalls. Alternatively or additionally, the position of the entire molten crucible can be varied relative to the vertical. Thus, the height of the molten crucible, and therefore the height of each liquid level of the molten vapor material contained or housed within the molten crucible, can be modified. In any case, by modifying the liquid level of the molten vapor material inside the molten crucible, the liquid level or filling level of the molten vapor material inside the molten crucible can be controlled and / or modified.

[0037] In a further example, the liquid level regulator is coupled to a controller. The controller is operable to control the operation of the liquid level regulator so as to maintain the filling level of the molten vapor material inside the evaporation crucible within a predetermined range. To that extent, the measuring device, the controller, and the liquid level regulator form or constitute a control loop, which in turn maintains the filling level of the molten vapor material inside the evaporation crucible within a predetermined range.

[0038] The measurement configuration provides quantitative measurement or determination of the instantaneous filling level of the molten vapor material inside the evaporation crucible. If a significant change in the filling level of the molten vapor material inside the evaporation crucible is detected, the controller can be activated to adjust the filling level of the evaporation crucible by the respective control operations of the liquid level regulator. In a typical use scenario, i.e., to coat a substrate, when a significant amount of molten vapor material evaporates into or from the evaporation crucible, the amount of molten vapor material inside the evaporation crucible will always decrease. This loss of molten vapor material inside the evaporation crucible is compensated by a fluid coupling or fluid connection with the molten vapor material, thereby ensuring that the molten vapor material is always supplied into the evaporation crucible.

[0039] For example, if the controller determines that the liquid level or filling level of the evaporation crucible has fallen below the minimum filling level, the control can operate to control the liquid level regulator accordingly to raise the liquid level of the molten evaporating material in the melting crucible, thereby also raising the liquid level of the molten material in the evaporation crucible via the fluid connection between the melting crucible and the evaporation crucible.

[0040] Alternatively, if the controller detects or determines that the filling level of the molten material inside the evaporation crucible exceeds or is tending to exceed the maximum filling level, the liquid level regulator can be controlled accordingly to reduce the liquid level or filling level of the molten evaporation material in the molten crucible, thereby immediately reducing the liquid level or filling level of the evaporation material inside the evaporation crucible.

[0041] In a further example, a liquid level regulator includes a lifting device that supports a molten crucible and is capable of correcting and / or adjusting the height of the molten crucible relative to the ground. The lifting device may include a drive and a type of lifting arrangement such as a scissor lift. The lifting device is electrically controllable by the drive and works to raise or lower the vertical position of the molten crucible. In this way, the absolute or gross height of the liquid level of the molten vapor material inside the molten crucible and / or relative to the ground can be substantially varied.

[0042] In a further example, a liquid level regulator includes a displacement body that is variablely immersable in the molten vapor material inside a molten crucible, thereby varying the liquid level or filling level of the molten vapor material inside a molten cavity relative to the sidewall of the molten crucible or the sidewall of the molten cavity. The displacement body may include a solid made from, for example, a heat-resistant material. The displacement body is typically made from a material with a melting point higher than the melting point of the vapor material. Thus, the displacement body is at least partially or completely immersable in the molten vapor material, thereby inducing an increase in the liquid level of the molten vapor material inside the molten crucible or molten cavity.

[0043] In some examples, the displacement body can be immersed in the molten vapor material to increase or raise the liquid level of the molten vapor material inside the molten crucible or molten cavity. In further examples, the displacement body can be retracted from the molten vapor material to decrease or lower the liquid level of the molten vapor material inside the molten crucible or molten cavity.

[0044] In a further example, the cross-section of the displacement body viewed in a direction transverse to the direction of displacement, or perpendicular to the direction of displacement, for example, perpendicular to the vertical direction, is greater than 25%, 30%, 40%, or 50% of the respective cross-sections of the molten crucible or molten cavity. In this way, by raising or lowering the position of the displacement body relative to the molten crucible or molten cavity, the packing level of the molten vapor material inside the evaporation crucible can be varied over a relatively large range.

[0045] In further examples, the displacement body can be variably immersed in and / or variably withdrawn from or retracted from the molten crucible.

[0046] Specifically, by retracting the displacement body from the molten crucible or molten cavity, and thus raising the position of the displacement body perpendicular to the molten crucible or molten cavity, a fairly rapid and abrupt reduction in the filling level of the molten evaporating material inside the evaporating crucible can be provided. This can be beneficial for performing a fairly direct and rapid stopping procedure for the evaporating unit.

[0047] The displacement body can be connected to an electric drive or mechanically, and the electric drive is controllable by a controller of the evaporation unit. The drive can be implemented as a servo drive and can be connected to the displacement body by couplings such as rods or chains. The displacement body can be placed on top of the molten crucible. The material of the displacement body can have a volume mass density higher than the density of each of the evaporating materials. In this way, the displacement body tends to immerse or sink into the molten evaporating material under the action of gravity.

[0048] The electric drive can be configured to provide continuous, and therefore stepless, motion or positioning of a displacement body relative to the molten crucible or molten cavity. In this way, the level of molten vaporized material inside the molten cavity can be adjusted and / or controlled with considerable precision.

[0049] The implementation of a liquid level regulator with a displacement element may be preferred in examples or embodiments of evaporation units where the total weight of the molten crucible is relatively large.

[0050] In some cases, the volume of the molten crucible is greater than the volume of the evaporation crucible. In some cases, the volume of the molten crucible, and therefore the volume of the molten cavity, is twice the volume of the evaporation crucible. In some cases, the volume of the molten cavity is at least three times, at least four times, or at least five times the volume of the evaporation cavity in the evaporation crucible. In this way, the molten crucible can also be used as a storage crucible capable of housing and / or supplying a relatively large amount of molten evaporative material, which can, as required, be supplied to the evaporation crucible in proportion to the evaporation rate at which the molten evaporative material transitions to the gas phase, and therefore to the evaporated state, by the evaporation crucible.

[0051] Due to their relatively large volume, molten crucibles can also be used to melt evaporative material supplied as a solid at a relatively low temperature into molten evaporative material already contained inside the molten cavity. The relatively large volume of the molten cavity ensures that adding or supplying unmelted, fairly solid evaporative material into the molten evaporative material has little to no effect on the pressure fluctuations of the molten evaporative material inside the molten cavity.

[0052] In a further example, the molten crucible and the evaporative crucible are fluidically connected via a heating fluid coupling. The heating fluid coupling prevents the molten evaporative material from being cooled as it is transported between the molten crucible and the evaporative crucible. Furthermore, the heating fluid coupling allows the evaporative material to undergo a certain amount of heating, and in some cases an increase in temperature, as it flows from the molten crucible into the evaporative crucible.

[0053] In some examples, the heating fluid connector can enter the molten crucible from above. The heating fluid connector may include a first end that terminates inside the molten crucible, for example, inside the molten cavity. The heating fluid connector can extend from above into the molten cavity and therefore into the molten crucible and can be oriented vertically. This allows for fairly easy and straightforward raising and lowering of the molten crucible, for example, by the liquid level adjuster and / or its lifting device described above. The fact that a substantially vertically oriented portion of the fluid connector faces downward into the molten crucible is particularly beneficial for correcting the height or vertical position of the molten crucible while keeping the fluid connector fixed. Here, variations in the height of the molten crucible only vary the depth of immersion of the end of the fluid connector into the molten vapor material inside the molten cavity.

[0054] In other examples, the end of the heating fluid coupling facing or coupled to the molten crucible extends through the side wall of the molten crucible and into the side wall of the molten crucible near the bottom of the molten crucible. Here, when the molten crucible is attached to a lifting device and subjected to vertical positional fluctuations, the heating fluid coupling may include at least one flexible portion to adapt to changes in the height or position of the molten crucible.

[0055] In further examples, the evaporation unit also includes a dispensing unit capable of supplying a solid or molten evaporation material into a molten crucible. The dispensing unit may be positioned above the molten crucible and may be capable of supplying the evaporation material from above into the molten crucible. The dispensing unit may provide a controllable supply of the evaporation material into the molten crucible. In some examples, when the evaporation material is supplied in the form of a solid metal wire, the dispensing unit may be capable of supplying the metal wire into the molten evaporation material inside the molten crucible at, for example, a constant or adjustable rate. In other examples, when the evaporation material is supplied in granular form, the dispensing unit may be capable of supplying the granular material into the molten evaporation material inside the molten crucible at a respective rate.

[0056] In another example, when the evaporating material is supplied in the form of an ingot, the dispensing unit can be configured to slowly introduce a fairly large block of solid evaporating material into the molten material inside the molten cavity.

[0057] Typically, as further examples show, the dispensing unit is coupled to a controller, which can be operated to control the operation of the dispensing unit and thereby also control the supply of solid or molten vapor material into the molten crucible. Typically, the controller can be operated to maintain a constant fluid level of molten vapor material inside the molten crucible during the process of dispensing or melting the solid vapor material into the molten crucible or molten cavity.

[0058] In particular, when the vaporizing material is supplied, for example, as a solid ingot, lowering each vaporizing material into the molten vaporizing material can be combined with lowering the final vertical position of the molten crucible in order to maintain a fairly constant liquid level of the molten vaporizing material relative to the ground. In this way, the liquid level, and therefore the filling level, of the molten vaporizing material inside the vaporizing crucible can be kept substantially constant and unaffected by the supply of solid or molten vaporizing material into the molten crucible.

[0059] In further examples, the molten crucible is exposed to atmospheric pressure. Therefore, the molten crucible is not only placed outside the evaporation chamber but is also exposed to atmospheric pressure. Placing the molten crucible outside the evaporation chamber and outside any airtight seal is particularly beneficial for supplying solid or molten evaporative material into the molten crucible during the evaporation and coating process underway inside the evaporation chamber. Nevertheless, when exposed to atmospheric pressure, each atmospheric pressure must be taken into account by the controller in order to accurately derive the packing level of the molten evaporative material in the molten crucible. For example, when calculating or deriving the packing level of the molten evaporative material in the molten crucible based on the packing level of the molten evaporative material in the molten crucible, natural modifications or fluctuations of atmospheric pressure can and must be taken into account.

[0060] In another example of an evaporation unit, the measurement arrangement includes at least one of a fill level sensor and a scale coupled to the molten crucible. The fill level sensor is operable to measure the fill level of the molten material inside the crucible. The scale is operable to measure at least one of the weight of the molten crucible and the molten evaporative material inside the crucible. The fill level sensor is operable to quantitatively measure the fill level of the molten evaporative material. The fill level sensor can be implemented as a non-contact fill level sensor. The fill level sensor may include an optical sensor, which can precisely determine or quantitatively measure the distance to the surface of the liquid level of the molten evaporative material inside the crucible.

[0061] The filling level sensor can be mounted on the molten crucible, for example, on the housing of the molten crucible. Here, the filling level sensor can be fixed to the molten crucible and thus operable to measure, for example, the liquid level of the molten vapor material inside the molten crucible with respect to a reference of the molten crucible. In this example, when the molten crucible is subjected to a lifting operation by, for example, a lifting device of a liquid level regulator, the respective level adjustments provided by the liquid level regulator or lifting device must be taken into further consideration, in addition to the liquid level quantitatively measured by the filling level sensor.

[0062] In another example, the filling level sensor can be stationary and positioned facing, for example, from above, the surface of the liquid level of the molten vaporizing material inside the melting crucible. Here, with the filling level sensor stationary and fixed relative to the ground, the liquid level of the molten vaporizing material relative to the ground can be precisely determined and / or quantitatively measured.

[0063] In some examples, the fill level sensor includes a laser light source and its respective detector. The fill level sensor may include a laser-based distance measuring device that can quantitatively measure and / or determine the liquid level or distance or position of the surface of the molten vapor material inside the melting crucible.

[0064] An alternative method is provided for determining the level of molten vapor filling inside a molten cavity by a scale operable to measure at least one of the weight of the molten crucible and / or the weight of the vaporizing material inside the molten crucible. Here, the temperature of the molten vapor filling inside the molten crucible must also be determined in order to derive the level of molten vapor filling inside the molten crucible based on weight or mass measurement.

[0065] In some examples, the measurement setup includes both a fill level sensor and a scale. In some examples, the fill level sensor provides a measurement signal, and the controller derives the fill level of the molten evaporating material inside the evaporating crucible based on this measurement signal. Here, the measurement signal obtainable from the scale can be used as a backup signal, and thus can provide a redundant measurement in case the measurement provided by the fill level sensor fails. The reverse is also true; the measurement signal generated by the scale can be used as a measurement signal processed by the controller to derive the fill level of the molten evaporating material inside the evaporating crucible. In this case, the signal obtained from the fill level sensor can be used as a backup signal.

[0066] In some cases, the controller can process signals from both the fill level sensor and the scale simultaneously to determine if the measurement setup is functioning correctly. If either the signal obtained from the scale or the fill level sensor deviates from the other, at least one of the fill level sensor and the scale will malfunction. In this case, the controller can generate a warning and / or switch the evaporation unit to emergency mode.

[0067] In another embodiment, the disclosure also relates to a coating arrangement for coating a substrate with a metallic material by vapor phase growth, for example, physical vapor phase growth. The coating arrangement includes an evaporation chamber for receiving the substrate and further includes the evaporation unit described above. The evaporation unit includes an evaporation crucible located inside the evaporation chamber. The molten crucible of the evaporation unit is located outside the evaporation chamber of the coating arrangement. The molten crucible can be exposed to atmospheric pressure, thereby facilitating the supply of the evaporating material to the molten crucible during the coating process.

[0068] In some examples, the evaporation chamber is a vacuum chamber. The evaporation chamber is coupled to a vacuum pump, which can generate a vacuum, and therefore vacuum pressure, inside the evaporation chamber. The evaporation crucible is also subjected to the vacuum pressure inside the evaporation chamber. The evaporation crucible is fluidically coupled to the molten crucible. The evaporation crucible can be positioned at a higher level than the molten crucible. Because the evaporation crucible is exposed to vacuum pressure and the molten crucible can be exposed to atmospheric pressure, the evaporation crucible inside the evaporation chamber can be positioned at a substantially higher level than the molten crucible outside the evaporation chamber. The pressure difference can directly reflect the difference in height or vertical level between the liquid level of the molten evaporation material inside the molten crucible and the liquid level of the molten evaporation material inside the evaporation crucible.

[0069] When the evaporation crucible and / or evaporation chamber are undergoing maintenance, it is particularly beneficial to place the evaporation crucible above the molten crucible. Emptying the evaporation crucible can be done exclusively under the action of gravity, thereby allowing the molten evaporation material located inside the evaporation crucible to flow back into the molten crucible through the fluid connection.

[0070] In some examples, the substrate includes a sheet of steel or metal. In other examples, the substrate includes a continuous strip or strip of metal or steel to be coated with a metal or metal alloy vaporized material containing at least one or a combination of the following materials: zinc, aluminum, nickel, chromium, magnesium, or titanium.

[0071] In some examples, the coating arrangement is configured to cover the surface of the substrate with a corrosion-resistant layer or coating. In some examples, the vacuum coating system is configured to coat a strip metal substrate, such as steel, with a metallic material or metallic alloy containing at least one or more of the following materials, or a combination thereof, for example by physical vapor deposition (PVD).

[0072] Since the covering configuration includes the evaporation unit described above, all the configurations, functions, and benefits described above in relation to the evaporation unit also apply equally to the covering configuration, and vice versa.

[0073] In a further embodiment, the disclosure also relates to a method for deriving or determining the packing level of molten vaporizing material inside an evaporation crucible, wherein the evaporation crucible is located inside an evaporation chamber, for example, the covering arrangement described above. The evaporation crucible is fluidly coupled to a molten crucible. The molten crucible is located outside the evaporation chamber. The molten crucible is configured to melt a metal evaporation material, to contain a molten vaporizing material, and / or to heat the molten vaporizing material. The method includes the steps of quantitatively measuring at least one of the packing level and mass of molten vaporizing material inside a molten crucible outside the evaporation chamber, and deriving or determining the packing level of molten vaporizing material inside the evaporation crucible based on at least one of the packing level and mass of molten vaporizing material inside the molten crucible.

[0074] In some examples, deriving or determining the packing level of the molten vapor material further takes into account at least one of the following: the ambient pressure inside or around the molten cavity, the vacuum pressure inside the evaporation chamber, the temperature of the molten vapor material inside the molten cavity, and the temperature of the molten vapor material inside the evaporation crucible.

[0075] Typically, the method for deriving or determining the packing level of the molten vaporizing material inside the evaporation crucible is carried out by the evaporation unit and / or covering arrangement described above. To that extent, all the configurations, functions, and benefits described above in relation to the evaporation unit and covering arrangement are equally applicable to the method for deriving or determining the packing level of the molten vaporizing material, and vice versa.

[0076] In further examples, this method further includes the step of controlling or correcting the filling level of the molten vapor material inside the evaporating crucible by varying the level of the molten vapor material inside the molten crucible relative to the ground and / or the sidewalls of the molten crucible, and thus inside the molten cavity of the molten crucible. In some examples, this method can provide or configure a control mechanism that can maintain the liquid level, and therefore the filling level, of the molten vapor material in the evaporating crucible within a predetermined range. The final correction, e.g., rise and fall, of the liquid level of the molten vapor material in the evaporating crucible can be measured indirectly, and the filling level of the molten crucible, and therefore each filling level of the evaporating crucible, can be adjusted accordingly by a liquid level regulator coupled to the molten crucible to maintain the liquid level or filling level of the molten vapor material in the evaporating crucible within a desired or predetermined range.

[0077] Numerous examples of methods for deriving or determining the evaporation unit, covering arrangement, and filling level of the molten evaporation material will be described in more detail below with reference to the drawings. [Brief explanation of the drawing]

[0078] [Figure 1] This diagram schematically shows a covering arrangement with an evaporation unit. [Figure 2] This diagram schematically illustrates a further example of an evaporation unit. [Figure 3] This diagram schematically illustrates a further example of an evaporation unit. [Figure 4] This is a schematic diagram showing the details of an example of a molten crucible. [Figure 5]This is a diagram showing an example of an evaporation crucible. [Figure 6] This figure shows another example of an evaporation crucible. [Figure 7] This figure shows further examples of evaporation crucibles. [Figure 8] This is a block diagram of the evaporation unit and covering arrangement. [Figure 9] Figure 5 shows a schematic three-dimensional diagram of a portion of an evaporation crucible. [Figure 10] This is a flowchart illustrating a method for deriving or determining the filling level of molten vaporized material. [Figure 11] This is a flowchart illustrating a method for adjusting or controlling the evaporation rate of an evaporation unit. [Modes for carrying out the invention]

[0079] Figures 1 to 9 show numerous examples of coating arrangements 5 including the evaporation unit 10. The coating arrangement 5 can be mounted to coat a metal substrate with a metallic material. The coating arrangement 5 can be specifically configured to coat a steel strip or sheet with a corrosion-resistant coating comprising at least one or a combination of materials such as zinc, aluminum, nickel, chromium, magnesium, or titanium.

[0080] The coating arrangement 5 is configured to evaporate the molten vapor material 12 to produce a vapor material 14, which is then deposited on the surface of the substrate 2. The coating arrangement 5 is configured to coat the substrate 2 via vapor phase growth, particularly via physical vapor phase growth.

[0081] The covering arrangement 5 includes an evaporation unit 10. The evaporation unit 10 includes an evaporation crucible 40 inside an evaporation chamber 50. The evaporation unit 10 further includes a molten crucible 20 outside the evaporation chamber 50, and the molten crucible 20 is fluidically connected to the evaporation crucible 40. The fluid connection between the molten crucible 20 and the evaporation crucible 40 is provided by a fluid connection 30. The fluid connection 30 includes a fluid guide pipe 32, which is equipped with a heating element 35. The fluid connection 30 includes an end 33 that is immersed in the molten evaporation material 12 provided or housed in the molten crucible 20. The fluid connection 30, and therefore the pipe 32, includes an opposite longitudinal end 34 that is fluidly connected to the evaporation crucible 40.

[0082] The fluid coupling 30 permanently fluid-couples the molten crucible 20 and the evaporation crucible 40. Thus, the filling level 48 of the molten evaporation material 12 inside the molten cavity 23 of the molten crucible 20 always corresponds to and / or correlates with the respective filling levels 48 of the molten evaporation material 12 inside the evaporation crucible 40.

[0083] For melting the evaporative material inside the molten cavity 23 and / or for housing the molten evaporative material 12 inside the molten cavity 23, the molten crucible 20 is equipped with a heating device 25. The end 33 of the fluid connection 30 is immersed in the molten evaporative material 12. In this way, impurities of the molten evaporative material 12 that have accumulated on the surface of the molten material 12 are substantially prevented from entering the end 33.

[0084] The evaporation crucible 40 is located inside the evaporation chamber 50 and is exposed to a reduced pressure, such as a vacuum level pressure. In particular, the molten crucible 20 can be exposed to atmospheric pressure P2. The evaporation crucible 40 inside the evaporation chamber 50 is subjected to a vacuum pressure p1. The evaporation crucible 40 is also equipped with a heater 45, which can heat the molten evaporation material 12 in the evaporation crucible 40 to such an extent that a considerable amount of the molten evaporation material 12 transitions to the evaporation material 14 and thus to the gas phase. The gaseous evaporation material 14 can exit the evaporation crucible 40 through an outlet 46, which may be equipped with a nozzle section 47, which causes a jet or accelerated stream of the evaporation material 14 to strike the surface of the substrate 2.

[0085] The inside of the evaporation chamber 50 is connected to a vacuum 53. The evaporation chamber 50 includes a chamber wall 51 and forms or constitutes a vacuum chamber 52.

[0086] The fluid connector 30 extends through the chamber wall 51 and provides permanent fluid communication between the evaporation crucible 40 and the melting crucible 20.

[0087] In some examples, the molten crucible 20 serves to melt a solid evaporating material, which can be supplied by the delivery unit 70 shown in Figure 2. This provides a constant supply of the molten evaporating material 12 to the molten crucible 20 and therefore to the evaporating crucible 40. This is particularly beneficial when the molten crucible 20 is located outside the evaporating chamber 50 and therefore outside the vacuum chamber 52. The molten crucible 20 can be provided in an unencapsulated configuration. The molten crucible 20 can be permanently exposed to atmospheric pressure. This provides a fairly easy and straightforward supply of the evaporating material to the molten crucible 20.

[0088] A permanent fluid connection between the molten crucible 20 and the evaporation crucible 40 allows for adjustment of the fluid level or filling level 48 inside the evaporation crucible 40 by correspondingly adjusting the filling level 28 of the molten evaporation material 12 in the molten crucible 20. Furthermore, since pressure p1 is lower than pressure p2, the molten crucible 20 can be positioned at a lower height than the evaporation crucible 40. The height difference Δh can be easily compensated by the pressure difference using the following formula.

[0089]

number

[0090] To adjust or control the filling level 48 inside the evaporation crucible 40, the filling level 28 of the molten evaporation material 12 inside the molten crucible 20 is measured and adjusted. This can be provided by a liquid level regulator 60 shown in Figures 1 and 2, or by a liquid level regulator 160 shown in Figure 3. The liquid level regulator 60 includes a lifting device 61, which can vary or adjust the height or vertical position of the entire molten crucible 20. In the example shown, the liquid level regulator 60 includes a scissor lift 62, which is controllable by a controller 90. Naturally, this scissor lift 62 is operable by an electric drive that is operated or controlled by the controller 90. By raising or lowering the lifting device 61, the vertical position of the entire molten crucible 20 can be varied relative to the ground 1.

[0091] Accordingly, the level 28 of the molten vaporizing material 12 relative to the ground 1 can be varied and adjusted by raising or lowering the molten crucible 20. Since the vaporizing crucible 40 is fixed inside the vaporizing chamber 50, each raising or lowering of the level 28 of the molten vaporizing material 12 in the molten crucible 20 has the corresponding effect on the level 48 of the molten vaporizing material 12 inside the vaporizing crucible 40.

[0092] Figure 3 shows another example of a liquid level regulator 160, which includes a displacement body 161 configured to be immersed in the molten vaporizing material 12 of the molten crucible 20. The liquid level regulator 160 includes a drive unit 163, which is also operable or controllable by a controller 90. The drive unit 163 is connected to the displacement body 161 via a coupler 162. The coupler 162 may include at least one of a rod and a chain. The displacement body may be a solid made from a material having a melting temperature above the melting temperature of the vaporizing material 12 inside the molten cavity 23.

[0093] Furthermore, the material of the displacement body 161 can contain a higher density than the density of the molten vaporized material 12. In this way, the displacement body 161 can be easily immersed or submerged in the molten vaporized material 12 under the action of gravity.

[0094] By lowering or immersing the displacement body 161 into the molten vaporized material 12, the level of filling 28 of the molten material 12 against the side walls 21 of the molten cavity 23 can be increased, which results in the respective modification and / or adjustment of the level of filling 48 of the molten vaporized material 12 inside the vaporization crucible 40.

[0095] In the example shown in Figure 1, the molten crucible 20 is open to the top and the fluid connection 30, and the pipe 32 extends from above into the molten vapor material 12. Here, only the immersion depth of the end 33 of the pipe 32 is varied by raising or lowering the molten crucible 20 using the lifting device 61.

[0096] In the alternative examples shown in Figures 2 and 3, the pipe 32 extends through the lower part of the side wall 21 of the molten cavity 23, and the end 33 of the pipe 32 can extend through the side wall 21 near the bottom 22 of the molten cavity 23.

[0097] In the example of Figure 2, where the liquid level regulator 60 includes a lifting device 61, the pipe 32 may include a flexible portion 36 to compensate for the fluctuating height between the ends 33 and 34 located on either side of the pipe 32. In the example of Figure 2, the end 43 of the pipe 32 extends through the bottom 42 of the evaporation crucible 40. In the example of Figure 1, the end 34 extends through the lower part of the side wall 41 of the evaporation crucible 40, adjacent to, near, or close to the bottom 42. The example of the liquid level regulator 160 according to Figure 3 may be useful for such examples of the covering arrangement 5 or evaporation unit 10 when the molten crucible 20 contains significant mass or weight.

[0098] The evaporation unit 10 further includes a measuring setup 80 coupled to a molten crucible 20, the measuring setup 80 being operable to quantitatively measure at least one of the filling level 28 of the molten evaporation material 12 in the molten cavity 23 and the mass of the molten evaporation material 12 in the molten crucible 20 or the molten cavity 23. For this purpose, the measuring setup 80 includes at least one of a liquid level detector 81 and a scale 84, as shown in Figure 4.

[0099] Figure 4 shows a melting unit 18 including a molten crucible 20. The melting unit 18 includes a carrier 24 or chassis which includes or forms a receptacle 26 sized to receive or house the molten crucible 20. The molten crucible 20 is positioned inside the receptacle 26. The molten crucible 20 includes a cup-shaped molten cavity 23. The bottom and / or side walls of the molten cavity 23 are covered with or provided with an insulating material 27. The insulating material 27 and / or the molten cavity 23 are thermally coupled to a heating device 25, thereby heating and thus melting the contents inside the molten cavity 23.

[0100] The receptacle 26 of the carrier 24 may include a bottom 22, on which the molten crucible 20 is positioned and supported. To measure the weight of the entire molten crucible 20, the entire carrier 24 can be placed on a scale 48. Since the weight of an empty molten crucible 20 is constant, the weighing of the molten crucible 20 with the evaporating material 12 directly indicates the total weight, and therefore the mass, of the evaporating material 12.

[0101] The liquid level detector 81 can be installed or fixed to the carrier 24. In this way, the position of the liquid level detector 81 relative to the molten crucible 20 and thus the side wall 21 is constant and maintained. In other examples, the liquid level detector 81 can be fixed to a base or the ground 1. Here, the liquid level detector 81 can be operated to determine and / or quantitatively measure the absolute level or height of the surface of the molten vaporized material 12 contained inside the molten cavity 23.

[0102] The liquid level detector 81 may include a distance meter 82, which can precisely measure the distance between the surface of the molten vaporized material 12, and thus between the filling level 28 and the side wall 21. In some examples, the liquid level detector 81 includes a light source and a photodetector to measure the distance between the liquid level detector and the surface of the molten vaporized material 12 in reflective geometry. In some examples, the liquid level detector includes a laser-based distance measuring device.

[0103] In the examples shown herein, the measuring setup 80 includes both a liquid level detector 81 and a scale 84, allowing for the quantitative determination or measurement of the amount or mass of molten vaporized material 12 inside the molten cavity 23, and thus the filling level 28, in a redundant manner. The redundant, i.e., dual measurement of the filling level 28 within the molten cavity 23 improves the accuracy and reliability of each quantitative measurement. In addition, the measurement or determination of the filling level becomes considerably more fail-safe.

[0104] The scale 84 and the liquid level detector 81 are coupled to the controller 90 in a signal-transmission manner. Both the scale 84 and the liquid detector 81 are configured to generate an electrical measurement signal to be processed by the controller 90 in order to quantitatively determine the filling level 28 of the molten vaporized material 12 inside the molten cavity 23.

[0105] The measurement setup 80 may further include at least one of a temperature sensor 86 and a pressure sensor 85, as shown in Figure 8. The temperature sensor 86 can determine the temperature of the molten vaporized material 12 inside the molten cavity 23. Knowing the weight of the molten vaporized material 12 inside the molten cavity 23 allows for a precise determination of the filling level 28, taking into account the temperature dependence of the density of the vaporized material 12. Naturally, the internal geometry of the molten cavity 23 is known.

[0106] The temperature sensor 86 may include a pyrometer and can therefore be configured to determine the temperature of the molten vaporized material 12 in a non-contact manner, for example, by placing the temperature sensor 86 on the molten vaporized material 12.

[0107] The controller 90 is further connected to a pressure sensor 87 and a temperature sensor 88 located inside or coupled to the evaporation chamber 50. The pressure sensor 87 can quantitatively measure the vacuum pressure p1 inside the evaporation chamber 50 or the vacuum chamber 52. In addition, it can also determine and / or quantitatively measure the temperature inside the evaporation chamber 50 and / or inside the evaporator 38. The temperature sensor 86 can also be implemented as a pyrometer. The pressure sensor 87 can be separately located inside the vacuum chamber 52 or integrated with the vacuum pump 53.

[0108] By quantitatively measuring the filling level 28 of the molten crucible 20, having knowledge of the instantaneous environmental pressure p2 and vacuum pressure p1 inside the evaporation chamber 50, and further having knowledge of the height difference between the molten crucible 20 and the evaporation crucible 40, the controller 90 can derive the filling level 48 of the molten evaporation material 12 inside the evaporation crucible 40.

[0109] Naturally, the evaporation unit 10 and the measuring arrangement 80 are suitably calibrated. As shown in Figure 5, the initial calibration can be achieved by first filling the evaporation crucible 40 with molten evaporation material 12 through the pipe 32. Here, the evaporation operating crucible 40 may be equipped with at least one fill level sensor 94, 95. In this example, two fill level sensors 94, 95 are schematically shown at different heights or different vertical positions. Fill level sensor 94 can define or correlate to the minimum fill level 74 of the evaporation crucible 40. Fill level sensor 95 can define or match to the maximum fill level 75. Fill level sensors 94, 95 can be implemented as fill level sensors based on electrical contacts. Each of the fill level sensors 94, 95 may include two electrical contacts, which are electrically connected by the conductive evaporation material 12. Therefore, the filling level sensors 94 and 95 can be operated to easily detect the presence of the evaporating material 12 and the position of each filling level sensor 94 and 95.

[0110] The fill level sensors 94 and 95 cannot be used further while the evaporator 38 is operating. The fill level sensors 94 and 95 can be signal-transmitted to the controller 90 to generate an alarm signal only when the fill level 48 falls below the minimum fill level 74 or when the fill level 48 exceeds the maximum fill level 75.

[0111] After the evaporation unit 10, and therefore the measurement setup 80, has been properly calibrated, knowledge of the pressure difference between p1 and p2 and the absolute height of the filling level 28 relative to the ground 1 is generally sufficient to derive the filling level 48 of the evaporation material 12 inside the evaporation cavity 55 based on a quantitative measurement of the filling level 28 measured under atmospheric pressure.

[0112] By constantly measuring the ambient pressure p2 or atmospheric pressure, the controller 90 can also take note of any final corrections or variations in the ambient pressure. To compensate for such pressure changes, for example, due to the supply of non-molten or molten vaporized material into the molten crucible 20, and / or to compensate for fluctuations in the filling level 28, the controller 90 can operate the liquid level regulators 60, 160 to artificially correct the filling level 28 relative to the ground 1 or the sidewall 21 of the molten crucible 20 so as to maintain the filling level 48 within a predetermined range.

[0113] Alternatively, the controller 90 can be operated to vary the immersion depth of the displacement body 161 within the molten cavity 23.

[0114] The controller 90 can further control the heating elements 25, 35, and 45, which heat the evaporating material 12 inside the molten cavity 23, inside the fluid connector 30 or pipe 32, or inside the evaporation crucible 40.

[0115] Figures 5 to 9 show several examples of the evaporator 38. The evaporator 38 includes an evaporation crucible 40. The evaporation crucible 40 contains an evaporation cavity 55. The evaporation cavity 55 includes a bottom inlet 56 and an outlet 46 adjacent to or near the top 44. The outlet 46 may include a nozzle section 47 projecting outward, the nozzle section 47 having a diameter or cross-section that converges or narrows toward its free end.

[0116] To that extent, the nozzle section 47 is operable to accelerate the flow or stream of the gaseous evaporating material 14 toward the substrate 2.

[0117] The evaporation crucible 40 includes a bottom section 49 through which a fluid connection to the pipe 32 is provided. The bottom section may include a bottom 42. The bottom 42 may have a planar shape as shown in Figure 7, or it may have a curved profile as shown in Figure 6. In the example of Figure 5, the lower sidewall section 43 of the sidewall 41 adjacent to the bottom 42 is funnel-shaped and integrates with the end 34 of the pipe 32. Here, the bottom 42 may be formed by the lower end of the inclined lower sidewall section 43.

[0118] The evaporation cavity 55 is separated into a liquid storage section 57 and an evaporation section 58 located above the liquid storage section 57. In the terminology of this specification, the liquid storage section 57 is the portion of the evaporation cavity 55 that is completely occupied by the molten or liquid evaporation material 12. The evaporation section 58 is located above the liquid storage section. The size of the liquid storage section 58 can increase with the supply of the molten evaporation material 12 into the evaporation cavity 55. The increase in the liquid storage section 57 always comes at the expense of the evaporation section, and vice versa. Thus, the size of the liquid storage section 57 varies inversely to the size of the evaporation section 58.

[0119] When the evaporator 38 is used and heated to a suitable operating temperature, the molten evaporating material 12 located in the liquid storage section 57 evaporates into the evaporation section 58. The molten evaporating material 12 then evaporates and thus transitions into a gaseous evaporating material 14.

[0120] The evaporation rate at which the molten vaporizing material 12 undergoes a phase transition to a gaseous state depends on the temperature inside the evaporation chamber 50, and therefore inside the evaporation crucible 40, as well as the vacuum pressure p1. The evaporation rate also depends on the available surface area of ​​the liquid molten vaporizing material 12 adjacent to the evaporation section 58 from below.

[0121] If the evaporator 38 is heated to a significant operating temperature and the evaporation process should be stopped or interrupted immediately, the dissipation of heat becomes very difficult and may require relatively long intervals. In this case, by adjusting only the evaporation rate, the temperature of the evaporator 38 or the evaporation crucible 40 becomes very slow or sluggish.

[0122] In the examples shown in Figures 5 to 9, the liquid storage section 57 defines the horizontal cross-sectional area of ​​the evaporation cavity 55, which decreases in size toward the inlet 56 or the bottom 42. The cross-sectional area can change gradually or in individual steps as the height varies. The surface of the horizontal cross-sectional area is provided in particular by the specific design of the side walls 41, and especially by the geometry or design of the lower side wall section 43.

[0123] In the examples in Figures 5 and 7, the lower sidewall section 43 includes an inclined sidewall section, and the distance between the sidewall sections on either side decreases horizontally as each sidewall section approaches the bottom 42 or entrance 56. As shown particularly in Figures 5 and 7, the minimum fill level 74 and the maximum fill level 75 are located within the inclined or slanted lower sidewall section 43.

[0124] To that extent, by modifying the filling level 48 inside the evaporation cavity 55, the overall size of the evaporation surface of the liquid molten evaporation material 12 inside the evaporation cavity 55 can be precisely varied. This provides fairly precise control and adjustment of the evaporation rate while maintaining a fairly constant temperature of the evaporator 38, and such control and adjustment become effective.

[0125] Generally, in the examples shown, the surface normal 59 of the lower sidewall section 43 extends at an angle α with respect to the horizontal, where α > 0°, α > 10°, α > 15°, α > 20°, α > 30°, α > 45°, or α > 60°, and / or 80° > α > 10°, 70° > α > 20°, 60° > α > 30°, 50° > α > 40°, or α is approximately 45°.

[0126] In the example of Figure 6, the lower sidewall section 43 includes a curved or concave structure, where the angle α between the surface normal 59 and the virtual horizontal increases toward the bottom 42 and / or entrance 56. In this way, along with variations in the filling level 48, a well-defined nonlinear change in the evaporation surface of the liquid molten evaporation material 12 inside the evaporation cavity 55 can be provided.

[0127] The transverse or horizontal cross-section of the evaporation crucible 40 can be cylindrical in shape. The transverse or horizontal cross-section of the evaporation crucible 40 can also be rectangular or elliptical in shape. In the perspective view of Figure 9, which can correspond to the example in Figure 7, the evaporation crucible 40 has a rectangular cross-section. Here, the side wall 41 includes a front surface 41a on the opposite side of the rear surface 41b. The front and rear surfaces 41a, 41b are connected at their respective ends by longitudinally extending transverse side wall portions 41c, 41d.

[0128] The lower side wall section 43 includes a funnel-shaped converging structure toward the bottom 42. Here, the lower parts 43c and 43d of the lateral side wall sections 41c and 41d, respectively, are inclined toward the bottom 42 toward each other. The lower parts of the front and rear surfaces 41a and 41b, respectively, include a somewhat triangular or trapezoidal structure.

[0129] The geometric shapes shown are by no means limiting. Generally, only one lateral side wall section 41c, 43c, 41d, 43d is conceivable to be inclined relative to the side wall section located on the opposite side.

[0130] In some examples, the front surface 41a is aligned parallel to the rear surface 41b. In some examples, at least a portion of the front surface 41a is inclined relative to the rear surface 41b. Here, the horizontal distance between the front surface 41a and the rear surface 41b can decrease toward the bottom 42. To that extent, this can provide a greater reduction in the horizontal cross-sectional area of ​​the evaporation cavity, along with a reduction in height or level above the bottom 42, compared to an example where only the side walls 41c, 41d are inclined toward each other, and the front surface 41a and rear surface 41b extend substantially parallel to each other.

[0131] The longitudinal range of the lateral sidewall portions, and therefore the larger range of the lateral sidewall portions 41c, 41d compared to the lateral or horizontal range of the back and front surfaces 41a, 41b, is beneficial in providing a fairly elongated nozzle section 47, which can be beneficial in homogeneously dispersing the evaporating material 14 over a relatively large surface area.

[0132] The flowchart in Figure 10 shows a method for deriving or determining the packing level of the evaporating material inside the evaporating crucible 40. In the first step 100, at least one of the packing level and mass of the molten evaporating material 12 inside the molten crucible 20, and therefore outside the evaporating chamber 50, is quantitatively measured. In the second step 102, the vacuum pressure p1 inside the evaporating chamber 50 is determined. In the next step 104, or simultaneously with step 102, the ambient or atmospheric pressure p2 is also measured.

[0133] From this pressure difference, and by having knowledge of the geometry and / or position of the molten crucible 20 relative to the evaporating crucible 40, the filling level 48 of the molten vaporized material 12 inside the evaporating crucible 40 is derived and / or calculated in step 106. In a further optional step, the temperature of the molten vaporized material 12 inside the molten cavity 23 and / or inside the evaporating cavity 55 may also be taken into account to increase the accuracy of determining the filling level 48. Due to the temperature dependence of the density of the molten vaporized material 12, the temperature difference between the molten crucible 20 and the evaporating crucible 40 may cause a further deviation between the filling level 48 and the filling level 28. Such effects can be compensated for by measuring these temperatures.

[0134] Furthermore, in subsequent processes, or through control loops of multiple of the above processes, the controller 90 can be operated to modify, for example artificially, the filling level 28 or and / or surface height of the molten evaporative material 12 inside the molten crucible 23 by using the liquid level adjusters 60, 160. Thus, the filling level 48 of the stationary evaporative crucible 40 can be adjusted and controlled by raising or lowering the molten crucible 20 relative to the ground 1.

[0135] Similarly, for example, when the molten crucible 20 is to be positioned stationary relative to the ground 1, the filling level 28 can be artificially modified or controlled by the liquid level adjuster 160, i.e., by modifying or adjusting the immersion depth of the displacement body 161 in the molten evaporation material 12.

[0136] The flowchart in Figure 11 illustrates a further method for adjusting or controlling the evaporation rate of the operating unit 10. Specifically, this method uses an evaporation crucible 40, as particularly shown in Figures 5, 6, 7, 8, or 9. Thus, the horizontal cross-sectional area of ​​the side walls of the evaporation cavity 55 of the evaporation crucible 40 decreases toward the inlet 56 or bottom 42 of the evaporation crucible 40. Here, in the first step 200, the evaporation crucible 40 is filled with a certain amount of molten evaporation material 12, for example, via a fluid connector 30.

[0137] The initial filling level 48 of the molten vaporizing material is typically below the maximum filling level 75 and above the minimum level 74. Subsequently, or simultaneously with the initial filling of the evaporation crucible 40, in step 202, the temperature of the evaporation cavity 55 is raised or maintained at an evaporation temperature at which most of the molten vaporizing material 12 evaporates according to a first evaporation rate. In step 204, for example, based on the aforementioned indirect measurement of the filling level 48 of the molten vaporizing material 12 inside the evaporation crucible, the filling level 48 inside the evaporation crucible 40 can be reduced to vary, i.e., reduce, the surface of the molten vaporizing material 12 adjacent to the evaporation section 58 of the evaporation cavity 55.

[0138] By varying, for example increasing or decreasing, the size of the evaporation surface of the molten evaporation material 12 inside the evaporation crucible 40, the evaporation rate at which the liquefied or molten evaporation material 12 transitions to an evaporated state and becomes evaporation material 14 is reduced in accordance with the reduction in the surface size of the molten material that occurs along with the decrease in the filling level 48. Similarly, the evaporation rate can also be increased, for example, by increasing the filling level 48 of the evaporation cavity 55. [Explanation of Symbols]

[0139] 1 ground 2 circuit boards 5. Covering arrangement 10 Evaporation Units 12. Molten materials 14 Evaporation materials 18 Melting Units 20 molten crucible 21 Side wall 22 Bottom 23. Molten cavities 24 Carriers 25 Heating tools 26 Receptacles 27. Insulation 28 Filling Levels 30 Fluid coupling 32 pipes 33 End 34 End 35 Heating tools 36 Flexible part 38 Evaporator 40 Evaporation crucible 41 Side wall 42 Bottom 43 Side wall section 44 Top 45 Heating tools 46 Exit 47 Nozzle Section 48 Filling Levels 49 Bottom section 50 Evaporation Chamber 51 Chamber Wall 52 Vacuum Chamber 53 Vacuum pump 55 Evaporation cavities 56 Entrance 57 Liquid Storage Section 58 Evaporation Section 59 Surface normal 60 Liquid Level Regulator 61 Lifting devices 62 Scissor Lift 70 Sending Unit 72 Funnel part 73 Curved section 74 Minimum filling level 75 Maximum Filling Level 80 Measurement arrangement 81 Liquid level detector 82 Distance meter 8 / 84 scale 85 Pressure Sensor 86 Temperature Sensor 87 Pressure Sensor 88 Temperature Sensor 90 Controllers 94 Filling level sensor 95 Filling level sensor 160 Liquid Level Regulator 161 Displacement body 162 Coupler 163 Drive unit

Claims

1. An evaporation unit (10) for evaporating a metal evaporation material, - The evaporation crucible (40) inside the evaporation chamber (50), - A melting crucible (20) located outside the evaporation chamber (50) and fluidly connected to the evaporation crucible (40), the melting crucible (20) includes a melting cavity (23) for melting a metal evaporation material, for housing a molten evaporation material (12), and / or for heating the molten evaporation material (12), - A measuring arrangement (80) coupled to the molten crucible (20) and operable to quantitatively measure at least one of the packing level (28) of the molten vapor material (12) in the molten cavity (23) and the mass of the molten vapor material (12) in the molten crucible (20), further operable to generate a measuring signal indicating at least one of the packing level (28) and mass of the molten vapor material (12), - A controller (90) connected to the measurement setup (80) and operable to derive the filling level (48) of the molten evaporating material (12) inside the evaporating crucible (40) based on the measurement signal received from the measurement setup (80) and The evaporation unit including the above.

2. The evaporation unit (10) according to claim 1, wherein the measuring arrangement (80) includes at least one of pressure sensors (85, 87) and temperature sensors (86, 88), the pressure sensors (85, 87) being operable to measure at least one of the ambient pressure (P2) inside or around the molten cavity (23) and the vacuum pressure (P1) inside the evaporation chamber (50), and the temperature sensors (86, 88) being operable to measure the temperature of the molten evaporation material (12) inside at least one of the molten cavity (23) and the evaporation crucible (40).

3. The evaporation unit (10) according to claim 2, wherein the controller (90) is operable to derive a filling level (48) of the molten vapor material (12) inside the evaporation crucible (40) by further taking into account at least one of the ambient pressure (P2) inside or around the molten cavity (23), the vacuum pressure (P1) inside the evaporation chamber (50), the temperature of the molten vapor material (12) inside the molten cavity (23), and the temperature of the molten vapor material (12) inside the evaporation crucible (40).

4. The evaporation unit (10) according to any one of claims 1 to 3, further comprising a liquid level regulator (60, 160) coupled to a molten crucible (20) and operable to vary the level of molten evaporating material (12) inside a molten cavity (23) relative to the ground (1) and / or the side wall (21) of the molten crucible (20).

5. The evaporation unit (10) according to any one of claims 1 to 4, wherein the filling level of the molten evaporation material (12) inside the evaporation crucible (40) is adjustable by varying the level or height of the molten evaporation material (12) inside the molten crucible (20).

6. The evaporation unit (10) according to claim 4 or 5, wherein liquid level regulators (60, 160) are coupled to a controller (90), and the controller (90) is operable to control the operation of the liquid level regulators (60, 160) so as to maintain the filling level (48) of the molten evaporation material (12) inside the evaporation crucible (40) within a predetermined range.

7. The evaporation unit (10) according to claims 4 to 6, wherein the liquid level regulator (60) supports the melting crucible (20) and includes a lifting device (61) that is operable to correct and / or adjust the height of the melting crucible (20) relative to the ground (1).

8. The evaporation unit (10) according to any one of claims 4 to 7, comprising a displacement body (161) which is variablely immersable in the molten evaporation material (12) inside the molten crucible (20), thereby causing the level of the molten evaporation material (12) inside the molten cavity (23) to vary relative to the side wall (21) of the evaporation crucible (20).

9. The evaporation unit (10) according to any one of claims 1 to 8, wherein a melting crucible (20) and an evaporation crucible (40) are fluidly connected via a heating fluid connector (30).

10. The evaporation unit (10) according to any one of claims 1 to 9, further comprising a dispensing unit (70) operable to supply a solid or molten evaporation material (12) into a melting crucible (20).

11. The evaporation unit (10) according to claim 10, wherein the dispensing unit (70) is coupled to a controller (90), and the controller (90) is operable to control the supply of a solid or molten evaporation material (12) into a melting crucible (20).

12. The evaporation unit (10) according to any one of claims 1 to 11, wherein the melting crucible (20) is exposed to atmospheric pressure.

13. The evaporation unit (10) according to any one of claims 1 to 12, wherein the measuring arrangement (80) includes at least one of a filling level sensor and a scale (84) coupled to the melting crucible (20), the filling level sensor (81) being operable to measure the filling level of the molten evaporating material (12) inside the melting crucible (20), and the scale (84) being operable to measure at least one of the weight of the melting crucible (20) and the molten evaporating material (12) inside the melting crucible (20).

14. A coating arrangement (5) for coating a substrate (2) with a metallic material by vapor phase growth, - An evaporation chamber (50) for receiving the substrate (2), - Evaporation unit (10) according to any one of claims 1 to 13 and The covering arrangement including the above.

15. A method for determining or deriving the filling level (48) of molten vapor material (12) inside an evaporation crucible (40) located inside an evaporation chamber (50), wherein the evaporation crucible (40) is fluidly connected to a molten crucible (20) outside the evaporation chamber (50), and the molten crucible (20) is configured to house and / or heat the molten vapor material (12), and the method is as follows: - A step of measuring at least one of the packing level (28) and mass of the molten vaporized material (12) inside the melting crucible (20) outside the evaporation chamber (50), - A step of deriving or determining the packing level (48) of the molten vaporized material (12) inside the vaporization crucible (40) based on at least one of the packing level (28) and mass of the molten vaporized material (12) inside the melting crucible (20) and The method comprising the above.

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