DE102020112201A1 - Device and method for coating containers - Google Patents

Abstract

The invention relates to a device for coating containers 9 by means of a plasma process, having at least one plasma station 15, which comprises at least one plasma chamber 8 with at least one treatment station with a container receptacle, in which at least one container 9 with a container interior 11 can be inserted and positioned at the treatment station The respective plasma chamber 8 has a vacuum line 14 connected to a vacuum unit, via which it can be at least partially evacuated, the respective plasma chamber 8 having a gas lance 12 which can be inserted into the container interior 11, the gas lance 12 being connected to a process gas line is, via which a process gas provided by a process gas generator reaches the container interior 11 for coating, the respective plasma chamber 8 being connected to at least one microwave generator 1, 1 ', 1 "and the microwave generator 1, 1', 1" being a control unit it, a signal generator 3 and a power supply unit 4, 4 ', the at least one microwave generator 1, 1', 1 "being a solid-state generator comprising a solid-state amplifier 2 and / or a microwave power amplifier and in the at least one plasma chamber 8 there is no sensor for controlling the microwave generator 1, 1 ', 1 "and no monitor diode for detecting its current output. The invention also relates to a method for coating containers 9 in a device for coating containers 9 by means of a plasma process.

Description

The invention relates to a device for coating containers with the features of the preamble of claim 1. The invention also relates to a method for coating containers with the features of the preamble of claim 8.

Such a device and such a method are for example from US 2018/0363141 A1 known. A provided process gas is introduced into a process chamber designed as a plasma chamber in which a container to be coated is located. This plasma-shaped process gas located in the process chamber is ignited and thus precipitates on the container. A solid-state generator is used to ignite the plasma-shaped process gas, in contrast to the magnetrons that are usually used. The energy of the solid-state generator required for ignition is introduced into the process chamber via an antenna which protrudes into the process chamber and is connected to the solid-state generator via a coaxial cable. The solid-state generator is controlled by a controller that receives the required data via a sensor located in the process chamber. Inside the process chamber there is a microwave-permeable quartz cylinder which surrounds the container to be coated and shields it in a liquid-tight manner from the space in which the antenna of the solid-state generator is arranged.

From the WO 03/100125 A1 it is known to arrange a plurality of plasma chambers on a rotating wheel. This supports a high production rate of containers per unit of time. In addition, double or multiple chambers can also be used as plasma chambers.

It is an object of the present invention to provide an apparatus and a method for coating containers in which a simplified construction of the apparatus is used.

This object is achieved for the generic device and for the generic method by the characterizing features of the respective independent claim. Advantageous developments of the device according to the invention and the method according to the invention are specified in the dependent claims.

Because the invention provides that, instead of a magnetron, a microwave generator, which ignites and maintains the plasma in the plasma chamber, is in the form of a solid-state generator or a microwave power amplifier, improved plasma deposition on the inner wall of the container is achieved generated, as this results in improved reliability and improved process control. The fact that there is no sensor for controlling the microwave generator and no monitor diode for detecting the current output in the plasma chamber simplifies the structure and also the control of the microwave generator.

The at least one microwave generator can advantageously be connected to the at least one plasma chamber via a waveguide via a quartz disk arranged at the point of introduction. As a result, the known configuration of the coating device can continue to be used and only the magnetron can be exchanged for a solid-state generator or a microwave power amplifier. An inexpensive conversion to achieve the advantages according to the invention is thus provided.

The at least one microwave generator can advantageously be connected directly to the at least one plasma chamber via a quartz disk arranged at the point of introduction. As a result, one component, usually a waveguide, is saved compared to the use of a magnetron, and an isolator for coupling in the magnetron is no longer required

• - Vorteilhafterweise kann sich der Ort der Einleitung im Bereich der Einleitung der Prozessgasleitung in axialer Richtung gegenüber einem Auslass der Gaslanze befinden. Dadurch kann die Gaslanze als Antenne verwendet werden und es ist keine Einkopplung über ein komplexes Quarzglas nötig. Darüber hinaus ist eine gezielte Anregung von gewünschten Moden über eine Längenänderung der Gaslanze möglich.

The point of introduction can advantageously be in the region of the introduction of the process gas line, on the surface of the at least one plasma chamber opposite this region and / or in a side region of the at least one plasma chamber. These points are particularly suitable for ensuring good functionality.

• The point of introduction can advantageously be in the region of the introduction of the process gas line in the axial direction opposite an outlet of the gas lance. This means that the gas lance can be used as an antenna and there is no need for coupling via a complex quartz glass. In addition, a targeted excitation of desired modes is possible by changing the length of the gas lance.

The device can advantageously have a cooling device integrated in a reactor block, the solid-state amplifier of the at least one solid-state generator being detachably connected to the reactor block. This means that when the solid-state amplifier is replaced, there is no need to work on the cooling circuit.

Advantageously, precisely one solid-state amplifier and / or precisely one control unit can be used and / or exactly one signal generator and / or exactly one power supply unit. In this way, components can be saved in devices that have several plasma chambers.

Because the plasma is generated in the method according to the invention without sensor detection of the amount of energy introduced and without regulation of the microwave generator, sensors in the plasma chamber for detecting the amount of energy introduced can be dispensed with, which leads to a simplification of the coating device. A further simplification of the coating device is achieved in that there is no regulation of the microwave generator as a function of the field constellation.

The method can advantageously be carried out in a device according to the invention. This results in the advantages given above for the embodiments of the device according to the invention.

The field constellation within the plasma chamber can advantageously be influenced by synchronized control of at least two microwave generators connected to the plasma chamber. As a result, the field constellation in the plasma chamber can be influenced and, for example, field inhomogeneities can be compensated for.

It goes without saying that the features and embodiments explained above and below are not only disclosed in the respectively specified combinations, but are also to be regarded as belonging to the disclosure on their own and in other combinations.

• 1 eine Prinzipskizze eines ersten Ausführungsbeispiels einer erfindungsgemäßen Vorrichtung,
• 2 eine Prinzipskizze eines zweiten Ausführungsbeispiels einer erfindungsgemäßen Vorrichtung,
• 3 eine Prinzipskizze eines dritten Ausführungsbeispiels einer erfindungsgemäßen Vorrichtung,
• 4 ein schematisches Blockschaltbild einer bevorzugten Ausführungsform einer erfindungsgemäßen Vorrichtung und
• 5 ein schematisches Blockschaltbild einer weiteren bevorzugten Ausführungsform einer erfindungsgemäßen Vorrichtung.

The invention is explained in more detail below on the basis of a preferred embodiment with reference to the drawings. The drawings show:

• 1 a schematic diagram of a first embodiment of a device according to the invention,
• 2 a schematic diagram of a second embodiment of a device according to the invention,
• 3 a schematic diagram of a third embodiment of a device according to the invention,
• 4th a schematic block diagram of a preferred embodiment of a device according to the invention and
• 5 a schematic block diagram of a further preferred embodiment of a device according to the invention.

In the 1 until 3 three embodiments of the invention are shown schematically, in which a plasma station 15th (please refer 4th ) exactly one plasma chamber 8th with exactly one treatment station for one container 9 , of a container interior 11 has, with associated device features. However, devices with more than one plasma chamber are also covered by the invention 8th and also from plasma chambers 8th that have more than one treatment station. There are several plasma chambers 8th before, they are regularly arranged on a rotating (not shown) plasma wheel, as is the case, for example, from the above WO 2017/102280 A2 is known. However, the invention is also not limited to a rotating plasma wheel, but in particular includes all rotating or non-rotating coating machines that have one or more process steps with fixed process gas mixtures and continuous process gas consumption.

In the first embodiment of the 1 is the container to be coated 9 already in its cradle in a reactor room 10 the plasma chamber 8th arranged and in the container interior 11 is a gas lance 12th from below through the opening of the container 9 introduced.

The containers to be coated 5 become the plasma station 15th supplied by means of known devices using known methods. The plasma chamber 8th has a vacuum line 14th on, which is connected to a vacuum unit (not shown) and which ensures that the pressure in the reactor chamber 10 is lowered by a process gas provided by a process gas generator (not shown) via a process gas line (not shown) which enters the lower end of the gas lance 12th opens into the container 9 to suck. This process gas is used to coat the inner wall of the container 9 . The coating is also carried out using known processes. The difference to the well-known methods lies in the use of an alternative microwave generator 1 in the form of a solid-state generator 1 . Such solid state generators 1 have recently been used in principle according to the above-mentioned prior art, but the invention dispenses with device parts compared to the known devices and methods, as will be explained further below.

In the plasma chamber 8th is in the reactor room 10 the container 9 Gas- and / or airtight inserted and positioned. A chamber base 23 has a vacuum line 14th on. This opens into the plasma chamber from below 8th or depending on the position of the gas lance 12th In addition, there is also a gas-permeable connection to the interior of the container 11 here. In particular, it can be provided that in one in the container interior 11 retracted state of the gas lance 12th the container interior 11 opposite the reactor room 10 is insulated, that is to say sealed, whereas the gas lance is in a lowered state 12th a gas-permeable connection between the container interior 11 and the reactor room 10 is created. Additional vacuum lines (not shown) and at least one ventilation line (not shown) can also be connected. The gas lance 12th can be coupled to further process gas lines (not shown) via the (central) process gas line, via which the different process gas compositions to the container interior 11 by means of the gas lance 12th are supplied.

• Zunächst wird der Behälter 9 unter Verwendung eines Eingaberades (nicht gezeigt) zum Plasmarad transportiert und in einem hochgeschobenen Zustand einer hülsenartigen Kammerwandung wird der Behälter 9 in die entsprechende Plasmakammer 8 eingesetzt. Nach einem Abschluss des Einsetzvorgangs wird die jeweilige Kammerwandung an dieser Plasmastation 15 in ihre abgedichtete Positionierung abgesenkt und zunächst gleichzeitig eine Evakuierung sowohl des Reaktorraumes 10 als auch des Behälterinnenraums 11 durchgeführt.

A typical treatment process at the plasma station 15th is briefly explained below using the example of a coating process:

• First is the container 9 using an input wheel (not shown) transported to the plasma wheel and in a pushed-up state of a sleeve-like chamber wall, the container 9 into the corresponding plasma chamber 8th used. After the insertion process has been completed, the respective chamber wall is attached to this plasma station 15th lowered into their sealed position and at the same time an evacuation of both the reactor room 10 as well as the interior of the container 11 carried out.

After sufficient evacuation of the reactor room 10 becomes the gas lance 12th into the interior of the container 11 retracted and a seal of the container interior by a displacement of a sealing element 11 opposite the reactor room 10 carried out. The pressure in the interior of the container can then be increased 11 can be further reduced. After a sufficiently low negative pressure has been reached, process gas is released through the gas lance 12th into the interior of the container 11 of the container 9 at the corresponding plasma station 15th initiated. After a sufficient supply of process gas, the microwave generator ignites 1 the plasma in the container interior 11 , with an ignition aid to facilitate ignition 13th is provided in the chamber sock 231. The ignition aid 13th protrudes into the vacuum line 14th the gas lance 12th opposite in. In particular, it can be provided that with the aid of the plasma both an adhesion promoter is applied to the surface of the interior of the container 11 as well as the actual barrier and protective layer is deposited.

As a microwave generator 1 becomes a solid state generator 1 - its design below in more detail in connection with the 4th and 5 - used that with the reactor room 10 the plasma chamber 8th via a waveguide 5 is connected and its confluence with the reactor room 10 over a quartz disk 7th is sealed gas-tight. Inside the waveguide 5 is still an optical emission spectroscope 6th arranged to monitor the process and ensure that the solid-state generator 1 emitted pulses can also be seen in the plasma. The intensity of the pulses is detected and a summation of all pulse intensities is carried out. This results in an evaluation basis that serves as a comparison to a target value defined in a recipe. This means, for example, that incorrect gas compositions and pressures can be detected. The optical emission spectroscope 6th is only used for monitoring, but not for regulation.

According to the invention, it is such that, in deviation from the prior art, on and in the reactor space 8th no sensors to control the solid-state generator 1 available. The control of the solid-state generator 1 will be discussed in more detail below in connection with the 4th and 5 described.

After completion of the plasma treatment, the interior of the container 11 ventilated to atmospheric pressure. At the same time, the gas lance can 12th from the interior of the container 11 be lowered. After adequate ventilation of the interior of the container 11 and the plasma chamber 8th The chamber wall is raised again up to preferably atmospheric pressure or ambient pressure. The coated container is then removed or transferred 5 to an output wheel (not shown).

The second embodiment shown in 2 is shown differs from the first embodiment of FIG 1 by having the solid state generator 1 '1' does not have a waveguide 5 with the reactor room 8th connected, but directly on the wall of the plasma chamber 8th is put on. In 2 are shown two positions in which the solid-state generator 1 , 1 'can be arranged. The solid-state generator couples in its first position 1 its energy in the same place in the reactor room 10 , as in the first embodiment of the 1 namely on the gas lance 12th opposite top surface. Here, too, are a quartz disk 7th for gas-tight closure of the solid-state generator 1 opposite the reactor room 10 and an optical emission spectroscope 7th available.

Alternatively or additionally, a further solid-state generator can be used 1' at the plasma chamber 8th to be appropriate. This is on the side wall of the plasma chamber 8th arranged and couples its energy via another quartz disk 7 ' into the reactor room 10 a.

Will be two solid state generators 1 , 1' can be used via a suitable synchronous control of these two solid-state generators 1 , 1' the field constellation within the reactor room 10 be influenced in such a way that the best possible deposition result of the process gas on the surface of the container interior 11 he follows.

The third embodiment of the 3 is the one who 2 very similar. It differs essentially in that it is a single solid-state generator 1" below the chamber base 23 is arranged. It does not feed its energy directly through the wall of the plasma chamber 8th in their reactor room 10 one, but via the vacuum line 14th , taking a quartz disk 7 " the gas-tight seal to this and thus also to the reactor room 10 guaranteed. The quartz disk is oriented in terms of its orientation 7 " in the axial direction opposite the outlet of the gas lance 12th and it is - as in the other exemplary embodiments - in the area of the quartz disk 7 " an optical emission spectroscope is available.

4th shows a schematic of how the solid-state generator 1 is built in principle and with the reactor room 10 connected is.

The solid-state generator 1 has an RF amplifier 2 on that from a signal generator 3 an input power P _in , which is specified via control signals arriving from the left, gets. Using the RF amplifier 2 from a power supply 4th is fed with a gain factor G (Vs) depending on the supply voltage of the transistors, this input power P _{in is} amplified and thus as output power Pout in the reactor space 10 the plasma chamber 10 that are in the plasma station 15th is fed in to ignite the plasma present there, as described above 1 has been described. By changing the voltage, the output power of the solid-state generator 1 be managed.

In 5 Figure 3 is another schematic embodiment of a solid state generator 1 shown. This is via a connection flange 16 with the waveguide 5 tied together. The waveguide 5 closes gas-tight over the quartz disc 7th with the reactor room 10 away.

The solid-state generator 1 has a solid state amplifier 2 on, the three main transistors on each side 22nd has (it can also be more or less, depending on the desired output) that draws its input power from a power supply unit 4th obtain. The power supply 4th receives its control signal from an input transistor 21 that serves as a preamplifier.

The input transistor 21 of the solid-state generator 1 is made by a signal generator 3 which is the input power for the solid-state generator 1 supplies and is not part of the same. The signal generator 3 is in turn with an external further power supply unit 4 ' tied together. Alternatively, the signal generator 3 also part of the solid-state generator 1 and be supplied by an external power supply unit.

The output signal of the solid-state amplifier 2 reaches a circulator 18th that provides the energy necessary for the ignition and maintenance of the plasma in the reactor room 10 is needed. The circulator 18th conducts the energy via the coupling into the reactor room 10 Further. The energy input 19th takes place in the illustrated embodiment via the waveguide 5 ; but this can also be done using other antenna concepts. In the circulator 18th the performance is judged. To control the energy input 19th instructs the solid-state generator 1 one incoming and one outgoing sensor connection 19th with a corresponding sensor, for example in the form of a monitor diode (which has no relation to the plasma chamber 8th has), are connected. In connection with the invention, it is important that, in contrast to the prior art, for example that specified above US 2018/0363141 A1 , no sensor is used, the conditions inside the reactor room 10 captured and the solid-state amplifier 1 also no information about the current performance, the energy input 19th from the reactor room 10 receives. Rather, it is through the sensor connection shown above 17th the incoming power (wave) is detected and through the sensor connection shown below 17th the returning power (wave) is detected. Through the sensor connections 17th it is only monitored whether the power from the circulator 18th comes out that is desired. To absorb the wrong directional output of the circulator 18th there is an absorption element, which can be designed as a water pocket or resistor, for example.

The following are specifications of what components are used and what key figures they have. These are only exemplary and in no way limit the invention.

As main transistors 22nd LD MOS, which are used for rectification, with a power of 250-330 W (possibly mirrored, so that a total of six such main transistors 22nd are present) and the input transistor 21 has an output of 20-150 W, ideally 25-100 W. The internal power supply unit 4th must be variable and has a voltage of 40-60 V DC, however, the external power supply 4 ' a voltage of only 5-12 V. The circulator 18th brings a power of about 2 kW over the range of 1-5 kW, ideally 1.5-4 kW in the Reactor room 10 a. The external power supply 4 ' supplies a voltage of 5-12 V. As a signal generator 3 a VCO or PLL operating in natural frequency is used, with an RF switch for pulsing, for example an excited quartz crystal. It has a power in the range of 0.5-15 mW, in particular about 1 mW.

The invention was described above using exemplary embodiments. It goes without saying that numerous changes and modifications are possible without thereby departing from the inventive concept on which the invention is based.

List of reference symbols

1, 1 ', 1' '

Microwave generators, in particular solid-state generators

2

Solid state amplifier

3

Signal generator

4.4 '

power adapter

5

Waveguide

6th

optical emission spectroscope

7, 7 ', 7' '

Quartz disk

8th

Plasma chamber

9

container

10

Reactor room

11

Container interior

12th

Gas lance

13th

Ignition aid

14th

Vacuum line

15th

Plasma station

16

Connection flange

17th

Sensor connection

18th

Circulator

19th

Energy input

20th

Absorption element

21

Input transistor

22nd

Main transistor

23

Chamber base

QUOTES INCLUDED IN THE DESCRIPTION

This list of the documents listed by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Patent literature cited

• US 2018/0363141 A1 [0002, 0035]
• WO 03/100125 A1 [0003]
• WO 2017/102280 A2 [0017]

Claims (10)

Device for coating containers (9) by means of a plasma process, having at least one plasma station (15) which comprises at least one plasma chamber (8) with at least one treatment station with a container receptacle, in which at least one container (9) with a container interior (11) can be used and positioned at the treatment station, the respective plasma chamber (8) having a vacuum line (14) connected to a vacuum unit, via which it can be at least partially evacuated, the respective plasma chamber (8) having a gas lance (12) which is in the container interior (11) can be introduced, the gas lance (12) being connected to a process gas line via which a process gas provided by a process gas generator reaches the container interior (11) for coating, the respective plasma chamber (8) having at least one microwave generator (1, 1 ', 1 ") is connected and the microwave generator (1, 1', 1") is a controller that is, a signal generator (3) and a power supply unit (4, 4 '), characterized in that the at least one microwave generator (1, 1', 1 ") is a solid-state generator, which is a solid-state amplifier ( 2) and / or a microwave power amplifier and in the at least one plasma chamber (8) no sensor for controlling the microwave generator (1, 1 ', 1 ") and no monitor diode for detecting its current output are present. Device according to Claim 1 wherein the at least one microwave generator (1, 1 ', 1 ") is connected via a waveguide (5) to the at least one plasma chamber (8) via a quartz disk (7, 7', 7") arranged at the point of introduction. Device according to Claim 1 wherein the at least one microwave generator (1, 1 ', 1 ") is connected directly to the at least one plasma chamber (8) via a quartz disk (7, 7', 7") arranged at the point of introduction. Device according to Claim 3 , the location of the introduction being in the area of the introduction of the process gas line, on the surface of the at least one plasma chamber (8) opposite this area and / or in a side area of the at least one plasma chamber (8). Device according to Claim 4 , wherein the point of introduction is in the region of the introduction of the process gas line in the axial direction opposite an outlet of the gas lance (12). Device according to one of the Claims 1 until 5 with a cooling device integrated in a reactor block, the solid-state amplifier (2) of the at least one solid-state generator (1, 1 ', 1 ") being detachably connected to the reactor block. Device according to one of the Claims 1 until 6th , with exactly one solid-state amplifier (2) and / or exactly one control unit and / or exactly one signal generator (3) and / or exactly one power supply unit (4) being present. Method for coating containers (9) in a device for coating containers (9) by means of a plasma process, which comprises the following process steps: - Insertion and positioning of a container (9) with a container interior (11) at a treatment station of a plasma chamber (8) a plasma station (15), - at least partial evacuation of the respective plasma chamber (8) in order to suck a process gas provided by a process gas generator into the container (9), - coating of the container interior (11) by means of plasma treatment, - generation of the plasma from the process gas by means of a microwave generator (1, 1 ', 1 ") in the form of a solid-state generator and / or a microwave power amplifier, characterized in that - the plasma is generated without sensor detection of the amount of energy entered and no regulation of the microwave generator ( 1, 1 ', 1 ") depending on the field constellation. Procedure according to Claim 8 , wherein it is in a device according to one of the Claims 1 until 7th is carried out. Method according to one of the Claims 8 or 9 , the field constellation within the plasma chamber (8) being influenced by synchronized control of at least two microwave generators (1, 1 ', 1 ") connected to the plasma chamber (8).

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