Aerosol jet printing device and method with fast turn-off

Abstract

The application belongs to the field of additive manufacturing, and specifically discloses an aerosol jet printing device and method capable of rapid cutoff, which comprises a jet printing head unit and a vacuum cutoff unit, wherein the jet printing head unit comprises an aerosol beam flow channel, an aerosol channel and a sheath gas channel connected with the inlet of the aerosol beam flow channel, and a nozzle connected with the outlet of the aerosol beam flow channel; the vacuum cutoff unit comprises a cutoff channel and a vacuum pumping assembly, one side of the cutoff channel is connected with an external hollow tube arranged beside the outlet of the nozzle or connected with the aerosol beam flow channel, and the other side of the cutoff channel is connected with the vacuum pumping assembly, so that under the action of the vacuum pumping assembly, negative pressure is formed, the aerosol in the aerosol beam flow channel is sucked into the cutoff channel to achieve rapid cutoff. The application changes the flow direction of the aerosol beam flow to achieve high response cutoff of the aerosol beam flow, the device has simple structure and high cutoff response, greatly reduces the limitation of the jet printing device on the structure of a jet printing substrate, and has wide application range.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of additive manufacturing, more particularly, to a quick-off aerosol jet printing device and method. BACKGROUND

[0002] In recent years, the electronic industry has gradually developed towards light weight, miniaturization and integration, especially the electronic products printed on flexible and curved substrates, which account for an increasing proportion in the market of wearable devices, intelligent integrated devices and intelligent packaging. However, the traditional printed electronic devices need to be improved in terms of manufacturing precision, integration and electrical performance. In view of the growing demand, high-resolution printed electronic technology has gradually developed and grown, and aerosol jet printing technology, as a new non-contact additive manufacturing technology, has many technical advantages such as high manufacturing resolution, low material loss, high printing speed and good substrate adaptability, and has been widely used in consumer electronics, medical electronics, aerospace and other fields. The working process of aerosol jet printing is: first, atomize the raw material into micron-sized particles; then, form an aerosol beam under the carrying and wrapping and restraining action of carrier gas and sheath gas; finally, the aerosol beam is sprayed out of the nozzle at a certain speed and deposited on the substrate to realize the jet printing forming of the design pattern. By adjusting the size and proportion of the carrier gas and the sheath gas, the line width and thickness of the jet printing line can be controlled, and the minimum line width can theoretically reach 10 μm.

[0003] Besides the line width accuracy of aerosol jet printing, the on-off response of aerosol jet printing is also an important factor affecting the overall printing quality. When the printing starts, the input carrier gas transports the aerosol flow to deposit on the substrate; when the printing ends, the carrier gas stops inputting, so that the aerosol is cut off. However, since the decrease and increase of the gas pressure in the printing head are both gradual processes, there is a large time delay in the response of the aerosol beam current when starting and stopping, and it takes a certain time to reach a stable state, that is, the on-off response of aerosol jet printing is low, which seriously affects the further application of this technology in fine pattern manufacturing. At present, there are mainly two schemes to improve the on-off response of aerosol jet printing: (1) blocking the aerosol beam outside the aerosol jet printing head, that is, by configuring a mechanical baffle and a control system outside, as shown in the article “Conformal printing of sensors on 3D and flexible surfaces using aerosol jet deposition”, Proc. SPIE 8691, Nanosensors, Biosensors, and Info-Tech Sensors and Systems 2013, 86910P (9 April 2013), when the aerosol jet printing stops, the control system gives a signal, and the external mechanical baffle moves to the nozzle, preventing the aerosol beam from depositing on the substrate surface below; when the aerosol jet printing starts, the mechanical baffle moves away from the nozzle. In this scheme, the on-off response of aerosol jet printing can reach 2 ms, but the external mechanical baffle and control system undoubtedly increase the complexity of the printing system, and the acceleration and deceleration of repeated movement may also cause contamination of the substrate. More importantly, since the mechanical baffle moves to the nozzle when the aerosol jet printing stops, the working distance between the nozzle and the substrate is greater than 5 mm, which is much larger than the best focusing point of the aerosol beam jetted from the nozzle, greatly affecting the printing effect. (2) cutting off the aerosol flow inside the aerosol jet printing head, that is, by designing a flow channel structure inside the printing head to control the flow direction of the gas. When the aerosol jet printing stops, the sheath gas no longer enters the printing head from the sheath gas flow channel, but enters the lower part of the gas collection chamber from the side flow channel, a part of the sheath gas is deflected in the direction opposite to the flow direction of the aerosol flow, so that the aerosol flow is reversed, preventing it from flowing to the nozzle, thereby achieving the cutting off of the aerosol flow, as shown in the aerosol flow blocking disclosed in CN111655382B. However, in this scheme, in addition to a part of the sheath gas deflected in the direction opposite to the flow direction of the aerosol flow, a part of the sheath gas will also be deflected in the same direction as the flow direction of the aerosol flow, and will be jetted from the nozzle, which will have a large airflow impact on the substrate, affecting the integrity of the printed pattern. SUMMARY

[0004] In view of the defects of the prior art, the application provides an aerosol jet printing device and method capable of rapid cutoff, aiming at solving the problem that the cutoff mode of the existing aerosol jet printing device affects the jet printing effect.

[0005] According to an aspect of the application, an aerosol jet printing device capable of rapid cutoff is provided, which specifically comprises a jet printing head unit and a vacuum cutoff unit, wherein: the jet printing head unit comprises an aerosol beam flow channel, an aerosol channel and a sheath gas channel connected with the inlet of the aerosol beam flow channel, and a nozzle connected with the outlet of the aerosol beam flow channel; the vacuum cutoff unit comprises a cutoff channel and a vacuum pumping assembly, one side of the cutoff channel is connected with an external hollow tube arranged beside the outlet of the nozzle or connected with the aerosol beam flow channel, and the other side of the cutoff channel is connected with the vacuum pumping assembly, so as to form negative pressure under the action of the vacuum pumping assembly, and the aerosol in the aerosol beam flow channel is sucked into the cutoff channel to achieve rapid cutoff.

[0006] Compared with the prior art, the above technical scheme conceived by the application has the advantages of high response, simple structure, and avoidance of pollution of the substrate, because the application sets a vacuum cutoff unit in the aerosol jet printing device, which can intercept the aerosol by using negative pressure and change the flow direction, so as to achieve rapid cutoff of the aerosol beam flow.

[0007] As a further preferred, the vacuum pumping assembly comprises a filter, a raw material recycling device and a vacuum pump, the filter is arranged between the cutoff channel and the vacuum pump, and the filter is connected with the raw material recycling device, for sending the aerosol in the cutoff channel into the raw material recycling device under the suction action of the vacuum pump.

[0008] As a further preferred, the vacuum pumping assembly further comprises a solenoid valve, the solenoid valve is arranged between the filter and the vacuum pump, for controlling the opening and closing of the channel between the vacuum pump and the filter.

[0009] As a further preferred, the vacuum pumping assembly further comprises a pressure regulating valve, the pressure regulating valve is arranged between the solenoid valve and the filter, for regulating the pressure.

[0010] As a further preferred, when the cutoff channel is connected with the external hollow tube, the distance H2 between the lowest point of the external hollow tube and the lowest point of the nozzle is less than 5mm, and the inner diameter D2 of the external hollow tube close to the nozzle is not less than the inner diameter D1 of the nozzle.

[0011] As a further preferred, when the cutoff channel is connected with the aerosol beam flow channel, the cutoff channel is a circular pipeline, the inner diameter D4 of the cutoff channel is equal to the inner diameter D3 of the aerosol beam flow channel, and at the same time, the inner diameter D4 of the cutoff channel is greater than the inner diameter D1 of the nozzle.

[0012] As a further preferred, when the cutoff channel is connected with the aerosol beam flow channel, the cutoff channel is a non-circular pipe, the height H1 of the cutoff channel is not less than the inner diameter D3 of the aerosol beam flow channel, the width W of the cutoff channel is not greater than the inner diameter D3 of the aerosol beam flow channel, and the width W of the cutoff channel is greater than the inner diameter D1 of the nozzle.

[0013] According to another aspect of the present application, a rapid cutoff method of the aerosol jet printing device is provided, which comprises: starting the jet printing head unit to perform jet printing, opening the vacuum pumping assembly when switching to a cutoff state, so as to form a negative pressure in the cutoff channel to suck the aerosol in the aerosol beam flow channel into the cutoff channel to achieve rapid cutoff, and closing the vacuum pumping assembly when switching to a jet printing state.

[0014] As a further preferred, when the vacuum pumping assembly comprises a solenoid valve, the vacuum pump is in a normally open state, and the vacuum pumping assembly is controlled to be opened or closed by opening or closing the solenoid valve; or, the vacuum pump and the solenoid valve are synchronously opened or closed to control the vacuum pumping assembly to be opened or closed.

[0015] As a further preferred, when the cutoff channel is connected with the aerosol beam flow channel, the negative pressure P generated by the cutoff channel in the cutoff state is not less than 0.1 times the pressure of the aerosol beam flow channel. N The following conditions need to be met:

[0016]

[0017] In the formula, A is the area of the intersection surface of the cutoff channel and the aerosol beam flow channel, g is the acceleration of gravity, m is the mass of the aerosol particles, H1 is the height of the cutoff channel, when the cutoff channel is a circular pipe, the inner diameter of the cutoff channel is the height thereof, θ2 is the included angle between the cutoff channel and the aerosol beam flow channel, Q is the sum of the sheath gas flow and the carrier gas flow, D3 is the inner diameter of the aerosol beam flow channel, and D5 is the diameter of the aerosol flow in the aerosol beam flow channel.

[0018] Overall, compared with the prior art, the above technical solutions conceived by the present application mainly have the following technical advantages:

[0019] 1. The application can turn and intercept the aerosol beam in its path by setting a vacuum interception unit, and achieve high response cutoff of the aerosol beam by changing the flow direction of the aerosol beam. The device has simple structure, high cutoff response, greatly reduces the restriction of the inkjet device on the inkjet substrate structure, and has wide application range. Compared with the traditional mechanical baffle blocking scheme, the space proportion of the external mechanical baffle and its support and control module on the side of the inkjet head is greatly reduced, the applicability of the aerosol inkjet technology to non-planar substrates is improved, and the risk of material overflow on the external mechanical baffle, material throwing out on the substrate due to acceleration and deceleration of the external mechanical baffle, and pollution is greatly avoided. Compared with the traditional pneumatic blocking scheme, the aerosol flow turning delay problem caused by the gas turning in the inkjet head is avoided, and the cutoff response can reach 2ms. At the same time, the application cuts off the entire aerosol beam, so that no gas flow flows out of the nozzle when the inkjet stops, avoiding the impact on the substrate and the influence on the printed pattern, greatly improving the aerosol inkjet precision and process stability.

[0020] 2. At the same time, the structure of the vacuum assembly is optimized, the opening and closing of the vacuum interception unit are controlled by the electromagnetic valve, the cutoff response is further improved, and the control process is simplified.

[0021] 3. In particular, the size of the cutoff channel is optimized according to the installation position and shape, and the negative pressure in the vacuum interception unit is adjusted to the corresponding range during use, which can realize complete cutoff of the aerosol beam under the premise of ensuring the cutoff response and startup response. BRIEF DESCRIPTION OF DRAWINGS

[0022] Figure 1 is a structural schematic diagram of the aerosol inkjet device provided by an embodiment of the application which can be quickly cut off;

[0023] Figure 2 is Figure 1 is an enlarged view of the nozzle and the cutoff channel in the aerosol inkjet device provided by the application;

[0024] Figure 3 is Figure 1 is a schematic diagram of the fluid flow direction and aerosol distribution when the aerosol inkjet device provided by the application is switched to the cutoff state;

[0025] Figure 4 is Figure 1 is a schematic diagram of the fluid flow direction and aerosol distribution when the aerosol inkjet device provided by the application is switched to the inkjet state;

[0026] Figure 5 is a structural schematic diagram of the aerosol inkjet device provided by another embodiment of the application which can be quickly cut off;

[0027] Figure 6 is Figure 5 The fluid flow direction and aerosol distribution schematic diagram when the aerosol jet printing device provided by the present application switches to the off state;

[0028] Figure 7 is Figure 5 The aerosol distribution fluid simulation result diagram when the aerosol jet printing device provided by the present application switches to the off state;

[0029] Figure 8 is Figure 5 The fluid flow direction and aerosol distribution schematic diagram when the aerosol jet printing device provided by the present application switches to the printing state;

[0030] Figure 9 is Figure 5 The aerosol distribution fluid simulation result diagram when the aerosol jet printing device provided by the present application switches to the printing state;

[0031] Figure 10 is Figure 5 The cross-sectional view of the printing head unit when the off channel of the aerosol jet printing device provided by the present application is a non-circular channel;

[0032] Figure 11 The structure schematic diagram of the aerosol jet printing device provided by another embodiment of the present application which can be quickly turned off;

[0033] Figure 12 The structure schematic diagram of the aerosol jet printing device provided by another embodiment of the present application which can be quickly turned off.

[0034] In all the drawings, the same reference signs are used to represent the same elements or structures, wherein:

[0035] 1-aerosol channel, 2-sheath gas inlet, 3-sheath gas channel, 4-gas mixing chamber, 5-aerosol beam flow channel, 6-off channel, 7-electromagnetic valve, 8-filter, 9-raw material recycler, 10-nozzle, 11-substrate, 12-vacuum pump, 13-pressure regulating valve, 14-external hollow tube. DETAILED DESCRIPTION

[0036] In order to make the purpose, technical scheme and advantages of the present application more clear, the present application is further described in detail below in combination with the drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application, and are not used to limit the present application.

[0037] As Figures 1 to 12As shown, the present application provides an aerosol jet printing device capable of rapid cutoff, which specifically comprises a jet printing head unit and a vacuum cutoff unit, wherein: the jet printing head unit comprises an aerosol beam flow channel 5, an aerosol channel 1 and a sheath gas channel 3 connected with the inlet of the aerosol beam flow channel 5, and a nozzle 10 connected with the outlet of the aerosol beam flow channel 5, the inner diameter D2 of the nozzle 10 is 0.05mm-5mm; the aerosol channel 1 is used for introducing carrier gas carrying aerosol particles, the sheath gas channel 3 is a sheath gas delivery channel formed inside the shell, the sheath gas channel 3 is provided with a sheath gas inlet 2 for introducing sheath gas, the aerosol channel 1 and the sheath gas channel 3 are mixed in a gas mixing chamber 4, the sheath gas surrounds the aerosol flow to form an aerosol beam flow and is sent into the aerosol beam flow channel 5, and finally is jetted out from the nozzle 10; Figure 1 、 10 The sheath gas channel 3 surrounds the gas mixing chamber 4, and the sheath gas channel 3 is open connected with the gas mixing chamber 4, Figure 5 、 Figure 12 The sheath gas channel 3 is closed connected with the gas mixing chamber 4, and any other way can be used to connect the sheath gas channel 3 with the gas mixing chamber 4;

[0038] The vacuum cutoff unit comprises a cutoff channel 6 and a vacuum pumping assembly, one side of the cutoff channel 6 is connected with an external hollow tube 14 arranged beside the outlet of the nozzle 10 or is connected with the aerosol beam flow channel 5, and the other side is connected with the vacuum pumping assembly, so that under the action of the vacuum pumping assembly, negative pressure is formed to suck the aerosol in the aerosol beam flow channel 5 into the cutoff channel 6 to achieve rapid cutoff, wherein Figure 1 and Figure 12 is an embodiment in which the cutoff channel 6 is connected with the external hollow tube 14, Figure 5 、 Figure 11 is an embodiment in which the cutoff channel 6 is connected with the aerosol beam flow channel 5.

[0039] The application can turn and intercept the aerosol beam in the path of the aerosol beam by setting the vacuum interception unit, and realize high response interception of the aerosol beam by changing the flow direction of the aerosol beam. The device has simple structure, high interception response, greatly reduces the limitation of the jet printing device on the jet printing substrate structure, has wide application range, greatly reduces the space ratio of the external mechanical baffle and its support and control module on the side of the jet printing head compared with the traditional mechanical baffle blocking scheme, improves the applicability of the aerosol jet printing technology to the non-planar substrate, and greatly avoids the risk of material overflow on the external mechanical baffle, the material being thrown out on the substrate due to acceleration and deceleration of the external mechanical baffle, and the aerosol flow turning delay problem caused by the gas turning in the jet printing head. The interception response can reach 2ms. At the same time, the application intercepts the entire aerosol beam, so that no gas flow flows out of the nozzle when the jet printing stops, avoiding the impact on the substrate and the influence on the printed pattern, greatly improving the aerosol jet printing precision and process stability.

[0040] Further, the vacuum assembly comprises a filter 8, a material recycling device 9 and a vacuum pump 12, the filter 8 is arranged between the interception channel 6 and the vacuum pump 12, and the filter 8 is connected with the material recycling device 9, for sending the aerosol in the interception channel 6 into the material recycling device 9 under the suction of the vacuum pump 12.

[0041] Further, the vacuum assembly further comprises an electromagnetic valve 7, the electromagnetic valve 7 is arranged between the filter 8 and the vacuum pump 12, for controlling the opening and closing of the channel between the vacuum pump 12 and the filter 8. After adding the electromagnetic valve 7, the vacuum assembly has two control modes, one is that the vacuum pump 12 adopts the normally open mode, and only the electromagnetic valve 7 is used to control the opening and closing of the vacuum assembly. This control mode is more convenient and fast. The other is that the vacuum pump 12 and the electromagnetic valve 7 are synchronously opened and closed. This control mode is more reliable.

[0042] Further, the vacuum assembly further comprises a pressure regulating valve 13, the pressure regulating valve 13 is arranged between the electromagnetic valve 7 and the filter 8, for regulating the pressure, and regulating the negative pressure value in the interception channel 6 to the negative pressure value range corresponding to the size parameters of the interception channel, so as to realize the complete interception of the aerosol beam under the premise of ensuring the interception response and the starting response.

[0043] Further, when the cutoff channel 6 is connected with the external hollow tube 14, the included angle θ1 between the external hollow tube 14 and the center line of the nozzle 10 is greater than 0° and less than 180°, so as to ensure that the negative pressure generated by the external hollow tube 14 has a component in the direction perpendicular to the center line of the nozzle 10 when the aerosol beam is cut off, and θ1 is preferably 90°, and meanwhile the external hollow tube 14 cannot be in the path of the aerosol beam outside the nozzle 10. The distance H2 between the lowest point of the external hollow tube 14 and the lowest point of the nozzle 10 is less than 5 mm, so as to avoid that the distance between the nozzle 10 and the substrate 11 is greater than 5 mm, and the inner diameter D2 of the end of the external hollow tube 14 close to the nozzle 10 is not less than the inner diameter D1 of the nozzle 10. When the aerosol beam is cut off, the absolute value of the negative pressure generated by the vacuum pumping assembly in the cutoff channel 6 is greater than the absolute value of the internal pressure in the nozzle 10, so as to enable all the aerosol particles in the aerosol beam channel 5 to be sucked into the cutoff channel 6.

[0044] Further, when the cutoff channel 6 is connected with the aerosol beam channel 5, as shown in Figure 2 , the cutoff channel 6 is composed of one or more channels with different sizes, and the included angle θ2 between the cutoff channel 6 connected with the aerosol beam channel 5 and the aerosol beam channel 5 is greater than 0° and less than 180°, and preferably θ2 is 90°, so as to enable the aerosol beam to flow out of the cutoff channel 6 completely and not to flow out of the nozzle 10 when the vacuum pumping assembly is adjusted to the negative pressure range corresponding to the size parameters of the cutoff channel.

[0045] When the cutoff channel 6 is a circular pipe, as shown in Figure 5 , the inner diameter D4 of the cutoff channel 6 is equal to the inner diameter D3 of the aerosol beam channel 5, and meanwhile the inner diameter D4 of the cutoff channel 6 is greater than the inner diameter D1 of the nozzle 10.

[0046] When the cutoff channel 6 is a non-circular pipe, Figure 10 the opening of the aerosol beam channel 5 is the cross-sectional shape of the cutoff channel, the height H1 of the cutoff channel 6 is not less than the inner diameter D3 of the aerosol beam channel 5, and the width W of the cutoff channel 6 is not greater than the inner diameter D3 of the aerosol beam channel 5, so as to ensure that the aerosol beam has a relatively low Reynolds number Re, so that it can flow out of the cutoff channel 6 completely and not to flow out of the nozzle 10 even at a relatively low negative pressure, and meanwhile the width W of the cutoff channel 6 is greater than the inner diameter D1 of the nozzle 10.

[0047] The specific process for high-precision preparation by using the aerosol jet printing device provided in the present application is as follows:

[0048] (1) as shown in Figure 1 or Figure 5As shown, aerosol jet printing is started, the sheath gas and carrier gas are opened, the sheath gas is introduced from the sheath gas inlet 2, passes through the sheath gas channel 3 and the gas collection chamber 4, and enters the aerosol beam current channel 5, the carrier gas carries the aerosol particles to form an aerosol flow, which enters the aerosol beam current channel 5 from the aerosol channel 1 through the gas collection chamber 4; the sheath gas surrounds the aerosol flow in the middle to form an aerosol beam current, which flows through the nozzle 10 and is deposited on the surface of the lower substrate 11, at this time the electromagnetic valve 7 is in a closed state, and the vacuum pump 12 is kept open or is opened and closed synchronously with the electromagnetic valve 7;

[0049] (2) Adjust the flow rate and proportion of the delivered carrier gas and sheath gas according to the set parameters, adjust the height of the nozzle 10 from the substrate 11, the jet printing speed and other parameters, until the jet printing effect is stable; wherein the carrier gas flow rate is 0-500 sccm, the sheath gas flow rate is 0-1000 sccm, the height of the nozzle 10 from the substrate 11 is 0-5 mm, and the jet printing speed is 0.1-100 mm / s;

[0050] (3) According to the requirements of the set jet printing pattern track, when it is necessary to cut off the aerosol beam current, as shown in Figure 3 or Figure 6 , the electromagnetic valve 7 is opened, a negative pressure is formed in the cut-off channel 6, the negative pressure value meets the negative pressure range requirements corresponding to different cut-off channel size parameters, so that the aerosol beam current is sucked into the cut-off channel 6 before being deposited on the surface of the substrate 11, thereby realizing the cut-off of the aerosol beam current; during the jet printing process, the rapid cut-off of the aerosol beam current under different flow rates can be realized by adjusting the negative pressure value;

[0051] (4) According to the requirements of the set jet printing pattern track, when it is necessary to start aerosol jet printing, as shown in Figure 4 or Figure 8 , the electromagnetic valve 7 is closed, the aerosol beam current switches the path again, and is directly deposited on the surface of the lower substrate 11 after flowing through the nozzle 10, and the aerosol jet printing process is restarted;

[0052] (5) Repeat steps (3) and (4) above to realize high-precision preparation of the set pattern, Figure 7 and Figure 9 are respectively the aerosol distribution fluid simulation result graphs when the aerosol jet printing device is switched to the cut-off state and the aerosol distribution fluid simulation result graphs when the aerosol jet printing device is switched to the jet printing state, proving the feasibility and reliability of the present application.

[0053] According to another aspect of the present application, a rapid stopping method of the aerosol jet printing device is provided, which comprises: starting the jet head unit, the sheath gas surrounding the aerosol flow to form an aerosol beam, flowing through the nozzle 10 and being deposited on the surface of the lower substrate 11, switching to the stopping state, opening the vacuum pumping assembly to form a negative pressure in the stopping channel 6, adjusting the negative pressure to a set range to suck the aerosol in the aerosol beam channel 5 into the stopping channel 6 to achieve rapid stopping, and closing the vacuum pumping assembly when restarting, so that the aerosol beam switches the path again, flows through the nozzle 10 and is directly deposited on the surface of the lower substrate 11, and the above steps are repeated to achieve high-precision preparation of the pattern.

[0054] Further, if the vacuum pumping assembly does not include a solenoid valve, the vacuum pump 12 is started when the vacuum pumping assembly is opened, and the vacuum pump 12 is closed when the vacuum pumping assembly is closed.

[0055] If the vacuum pumping assembly includes a solenoid valve, the vacuum pump 12 and the solenoid valve 7 are started when the vacuum pumping assembly is opened, and the vacuum pump 12 can be kept on and the solenoid valve 7 can be closed, or the vacuum pump 12 and the solenoid valve 7 can be closed synchronously when the vacuum pumping assembly is closed. The operation of opening and closing the vacuum pumping assembly by only relying on the solenoid valve 7 is more rapid and convenient.

[0056] Further, when the stopping channel 6 is connected with the aerosol beam channel 5, the negative pressure generated by the vacuum pumping assembly in the stopping channel 6 is required to suck all the aerosol particles in the aerosol beam channel 5 into the stopping channel 6 when the aerosol beam is stopped, that is, the negative pressure P generated by the vacuum pumping assembly in the stopping channel 6 is required to satisfy the following formula: N It is required to satisfy:

[0057]

[0058] In the formula, A is the area of the intersection surface of the stopping channel 6 and the aerosol beam channel 5, g is the acceleration of gravity, m is the mass of the aerosol particle, H1 is the height of the stopping channel 6, when the stopping channel 6 is a circular pipe, the inner diameter of the stopping channel 6 is the height thereof, θ2 is the included angle between the stopping channel 6 and the aerosol beam channel 5, Q is the sum of the sheath gas flow and the carrier gas flow, D3 is the inner diameter of the aerosol beam channel 5, and D5 is the diameter of the aerosol flow in the aerosol beam channel 5.

[0059] The aerosol beam is composed of the aerosol flow and the annular sheath gas flow surrounding the aerosol flow, and the maximum value D5max of the diameter D5 of the aerosol flow in the aerosol beam channel 5 is equal to the diameter D3 of the aerosol beam channel, that is, the negative pressure P generated by the vacuum pumping assembly in the stopping channel 6 is required to satisfy the following formula: max The negative pressure P generated by the vacuum pumping assembly in the stopping channel 6 is required to satisfy the following formula: N It is also required to satisfy:

[0060]

[0061] And when the vacuum assembly generates a negative pressure P in the cutoff channel 6 N When the cutoff channel 6 is connected with the aerosol beam flow channel 5, the aerosol particles can still be completely sucked into the cutoff channel 6, but the pressure in the internal flow channel of the jet printing head (including the aerosol beam flow channel 5, the cutoff channel 6, the aerosol channel 1 and the sheath gas channel 3) is too low, which causes a large time delay when the aerosol jet printing is started.

[0062] In summary, when the cutoff channel 6 is connected with the aerosol beam flow channel 5, the aerosol particles can still be completely sucked into the cutoff channel 6, but the pressure in the internal flow channel of the jet printing head (including the aerosol beam flow channel 5, the cutoff channel 6, the aerosol channel 1 and the sheath gas channel 3) is too low, which causes a large time delay when the aerosol jet printing is started. N The formula (1) and the formula (2) need to be satisfied at the same time, that is:

[0063]

[0064] The technical solutions provided by the present application are further described below according to specific embodiments.

[0065] Embodiment 1

[0066] An aerosol jet printing device capable of rapid cutoff includes a jet printing head unit and a vacuum cutoff unit. The jet printing head unit includes an aerosol beam flow channel 5, an aerosol channel 1, a sheath gas channel 3 and a nozzle 10. The vacuum cutoff unit includes a cutoff channel 6 and a vacuum assembly. One side of the cutoff channel 6 is connected with an external hollow tube 14, and the other side is connected with the vacuum assembly.

[0067] The inner diameter D1 of the nozzle 10 is 0.15 mm. The external hollow tube 14 is located on the side of the nozzle 10, one end of which is adjacent to the nozzle 10, and the other end is connected with the cutoff channel 6 through threads. The angle θ1 between the center line of the flow channel at the end of the external hollow tube 14 and the center line of the flow channel of the nozzle 10 is 90°. The horizontal distance L1 between the end of the external hollow tube 14 and the nozzle 10 is 0 mm. The inner diameter D2 of the outlet of the external hollow tube 14 is 0.5 mm. The distance H2 between the lowest point of the external hollow tube 14 and the lowest point of the nozzle 10 is 0.55 mm.

[0068] The rapid cutoff method of the aerosol jet printing device includes the following steps:

[0069] (1) Start the aerosol jet printing, open the sheath gas and the carrier gas, the sheath gas enters the aerosol beam flow channel 5 from the sheath gas channel 3 through the gas collection chamber 4, the carrier gas carries the aerosol particles to form an aerosol flow, which enters the aerosol beam flow channel 5 from the aerosol channel 1 through the gas collection chamber 4, the sheath gas surrounds the aerosol flow in the middle to form an aerosol beam flow, which flows through the nozzle 10 and is deposited on the surface of the lower substrate. At this time, the electromagnetic valve 12 is in the closed state, and the vacuum pump 12 is kept open.

[0070] (2) According to the set parameters, the carrier gas flow is adjusted to 20 sccm, the sheath gas flow is adjusted to 50 sccm, the height of the nozzle 10 from the substrate 11 is adjusted to 5 mm, and the jet printing speed is adjusted to 5 mm / s until the jet printing effect reaches stability;

[0071] (3) According to the set jet printing pattern track requirements, when the aerosol beam flow needs to be cut off, the electromagnetic valve 7 is opened, a negative pressure is formed in the cut-off channel 6 and the external hollow tube 14, the internal pressure of the external hollow tube 14 is -10 kPa, the aerosol beam flow switches the path after flowing through the nozzle 10, is sucked into the 6 cut-off channel by the external hollow tube 14, and the raw material enters the raw material recycler 9 through the filter 8, so as to prevent the aerosol beam flow from being deposited on the surface of the substrate 11, and the cut-off of the aerosol beam flow is realized;

[0072] (4) According to the set jet printing pattern track requirements, when the aerosol jet printing needs to be started, the electromagnetic valve 7 is closed, the aerosol beam flow switches the path again after flowing through the nozzle 10, and is directly deposited on the surface of the lower substrate 11, so as to restart the aerosol jet printing process;

[0073] (5) The steps (3) and (4) are repeated to realize the preparation of the set pattern with high precision.

[0074] Example 2

[0075] A kind of aerosol jet printing device that can be quickly cut off, including jet printing head unit and vacuum cut-off unit, jet printing head unit includes aerosol beam flow channel 5, aerosol channel 1, sheath gas channel and nozzle 10, vacuum cut-off unit includes cut-off channel 6 and vacuum pumping assembly, cut-off channel 6 one side aerosol beam flow channel 5 is connected, its other side is connected with vacuum pumping assembly.

[0076] The inner diameter D1 of the nozzle is 0.5 mm. The diameter D3 of the aerosol beam flow channel 5 is 1.5 mm. The cut-off channel 6 is composed of a channel, the cross section of the channel is circular, the cross section diameter D4 of the cut-off channel 6 is D3 = 1.5 mm, the length L2 of the cut-off channel 6 is 15 mm, and the included angle θ2 between the cut-off channel 6 and the aerosol beam flow channel 5 is 90°.

[0077] The rapid cut-off method of the above-mentioned aerosol jet printing device specifically includes the following steps:

[0078] (1) Start the aerosol jet printing, open the sheath gas and the carrier gas, the sheath gas enters the aerosol beam flow channel 5 from the sheath gas channel 3 through the gas collecting chamber 4, the carrier gas carries the aerosol particles to form an aerosol flow, which enters the aerosol beam flow channel 5 from the aerosol channel 1 through the gas collecting chamber 4, the sheath gas surrounds the aerosol flow in the middle to form an aerosol beam flow, which is deposited on the surface of the lower substrate after flowing through the nozzle 10, at this time, the vacuum pump and the electromagnetic valve are both in the closed state, and the two are synchronously switched on;

[0079] (2) according to the set parameters, the carrier gas flow is adjusted to 50 sccm, the sheath gas flow is adjusted to 200 sccm, the nozzle height from the substrate is adjusted to 4 mm, and the jet printing speed is adjusted to 5 mm / s until the jet printing effect is stable;

[0080] (3) according to the set jet printing pattern track requirements, at the position where the aerosol beam flow needs to be cut off, the vacuum pump 12 and the electromagnetic valve 7 are opened, the pressure regulating valve 13 is adjusted to-0.1 kPa, at this time, the aerosol beam flow changes the flow direction when flowing through the aerosol beam flow channel 5, flows out from the cut-off channel 6, after being filtered by the filter 8, the jet printing raw material enters the raw material recycler 9, and no aerosol beam flow is sprayed from the nozzle 10, so as to realize the cut-off of the aerosol jet printing;

[0081] (4) according to the set jet printing pattern track requirements, when the aerosol jet printing needs to be started, the electromagnetic valve 7 is closed, the aerosol beam flow flows through the nozzle 10 along the aerosol beam flow channel 5 again, and the pattern jet printing is started on the substrate 11, and the aerosol jet printing process is restarted;

[0082] (5) the above steps (3) and (4) are repeated to realize the high-precision preparation of the set pattern.

[0083] In the description of the present application, it should be understood that the terms "first", "second" are only for the purpose of description, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first", "second" can be explicitly or implicitly included one or more of the features. In the description of the present application, the meaning of "multiple" is two or more, unless otherwise specifically limited.

[0084] In addition, throughout the specification, the reference to "one embodiment"; "one embodiment", "one example" or similar language means that the specific features, structures or characteristics described in connection with the embodiment are included in at least one embodiment of the present application. Therefore, the appearance of the phrase "in one embodiment" and similar language throughout the specification may, but does not necessarily, all refer to the same embodiment.

[0085] Those skilled in the art will readily understand that the above description is only the preferred embodiment of the present application, and is not intended to limit the present application, and any modifications, equivalent replacements and improvements made within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. A quick cut-off aerosol jet printing device, characterized in that, The device comprises a jet printing head unit and a vacuum cutoff unit, wherein: the jet printing head unit comprises an aerosol beam flow channel (5), an aerosol channel (1) and a sheath gas channel (3) connected with the inlet of the aerosol beam flow channel (5), and a nozzle (10) connected with the outlet of the aerosol beam flow channel (5); the vacuum cutoff unit comprises a cutoff channel (6) and a vacuum pumping assembly, one side of the cutoff channel (6) is connected with the aerosol beam flow channel (5), and the other side of the cutoff channel (6) is connected with the vacuum pumping assembly to form negative pressure under the action of the vacuum pumping assembly, so that the aerosol in the aerosol beam flow channel (5) is sucked into the cutoff channel (6) to achieve rapid cutoff; Negative pressure generated by the shut-off channel (6) in the shut-off state P N The following conditions must be met: In the formula, is the area of the intersection surface of the cutoff channel (6) and the aerosol beam channel (5), g is the acceleration of gravity, m is the mass of the aerosol particles, is the height of the cutoff channel (6), when the cutoff channel (6) is a circular pipe, the inner diameter of the cutoff channel (6) is its height, is the angle between the cutoff channel (6) and the aerosol beam channel (5), is the sum of the sheath gas flow and the carrier gas flow, is the inner diameter of the aerosol beam channel (5), is the diameter of the aerosol flow in the aerosol beam channel (5).

2. The aerosol-jet printing apparatus of claim 1, wherein, the vacuum pumping assembly comprises a filter (8), a raw material recovery device (9) and a vacuum pump (12), the filter (8) is arranged between the cutoff channel (6) and the vacuum pump (12), and the filter (8) is connected with the raw material recovery device (9) to send the aerosol in the cutoff channel (6) into the raw material recovery device (9) under the suction of the vacuum pump (12).

3. The aerosol-jet printing apparatus of claim 2, wherein, the vacuum pumping assembly further comprises a solenoid valve (7) arranged between the filter (8) and the vacuum pump (12) to control the opening and closing of the channel between the vacuum pump (12) and the filter (8).

4. The aerosol-jet printing apparatus of claim 3, wherein, the vacuum pumping assembly further comprises a pressure regulating valve (13) arranged between the solenoid valve (7) and the filter (8) to regulate the pressure.

5. The aerosol-jet printing apparatus of claim 1, wherein, when the cutoff channel (6) is connected with the aerosol beam flow channel (5), the cutoff channel (6) is a circular pipe, the inner diameter D4 of the cutoff channel (6) is equal to the inner diameter D3 of the aerosol beam flow channel (5), and the inner diameter D4 of the cutoff channel (6) is greater than the inner diameter D1 of the nozzle (10).

6. The aerosol-jet printing apparatus of claim 1, wherein, when the cutoff channel (6) is connected with the aerosol beam flow channel (5), the cutoff channel (6) is a non-circular pipe, the height H1 of the cutoff channel (6) is not less than the inner diameter D3 of the aerosol beam flow channel (5), the width W of the cutoff channel (6) is not greater than the inner diameter D3 of the aerosol beam flow channel (5), and the width W of the cutoff channel (6) is greater than the inner diameter D1 of the nozzle (10).

7. The quick cut-off method of the aerosol jet printing apparatus according to any one of claims 1 to 6, wherein, Specifically: when the jet printing head unit is started for jet printing and needs to be switched to a cutoff state, the vacuum pumping assembly is opened to form negative pressure in the cutoff channel (6) to suck the aerosol in the aerosol beam flow channel (5) into the cutoff channel (6) to achieve rapid cutoff, and when the jet printing head unit needs to be switched to a jet printing state, the vacuum pumping assembly is closed.

8. The fast turn-off method of claim 7, wherein, when the vacuum pumping assembly comprises a solenoid valve (7), the vacuum pump (12) is in a normally open state, and the solenoid valve (7) is opened or closed to control the opening and closing of the vacuum assembly; or, the vacuum pump (12) and the solenoid valve (7) are synchronously opened or closed to control the opening and closing of the vacuum assembly.

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