Low-melting-point metal ink channels, ink filling systems, and printing systems

Abstract

A low-melting-point metal ink channel, an ink filling system and a printing system. The ink channel includes: a pipeline for conveying molten low-melting-point metal; at least one chamber disposed in the pipeline and communicating with the pipeline; at least one cleaning chamber exists in the at least one chamber for removing oxygen elements in the low-melting-point metal. The present invention prevents the problem of the reduction of the purity of the low-melting-point metal by using the cleaning chamber to remove impurities and purify the low-melting-point metal in the ink channel of the low-melting-point metal.

Description

Technical Field

[0001] The invention belongs to the technical field of low-melting-point metal application, and in particular relates to a low-melting-point metal ink channel, an ink filling system and a printing system. Background Art

[0002] With the continuous advancement of printed electronics technology, conductive fluids represented by low-melting-point metals (also known as liquid metals) have emerged, making it possible to print wires to make liquid metal flexible electronic circuits. This has not only changed the traditional PCB hard electronic circuit manufacturing model, but also greatly reduced the time and cost of electronic circuit manufacturing. Low-melting-point metal printing technology has unique advantages in the rapid manufacturing of flexible circuits, traditional PCBs, antennas and other electronic devices, and has a very broad application prospect.

[0003] Low-melting-point metals are easily oxidized in the air, which makes it easy for metal oxides to be mixed in the low-melting-point metals, resulting in reduced purity of the low-melting-point metals. Summary of the invention

[0004] In view of this, an object of the present invention is to provide a low-melting-point metal ink channel to solve the problem in the prior art that the purity of the low-melting-point metal is reduced due to the inclusion of metal oxides in the low-melting-point metal.

[0005] In some illustrative embodiments, the low-melting-point metal ink channel includes: a pipeline for conveying molten low-melting-point metal; at least one chamber arranged in the pipeline and connected to the pipeline; at least one cleaning chamber exists in the at least one chamber for removing oxygen elements in the low-melting-point metal.

[0006] In some optional embodiments, the cleaning chamber is connected to a pipeline through a first feed port and a first discharge port, wherein the first feed port is located at the top of the cleaning chamber, and the first discharge port is located at the bottom of the cleaning chamber; the cleaning chamber contains a filtrate floating on the surface of the low-melting-point metal, and the filtrate chemically reacts with metal oxides entrained in the low-melting-point metal.

[0007] In some optional embodiments, the filtrate is a 0.1 mol / L-0.2 mol / L sodium hydroxide solution.

[0008] In some optional embodiments, a second feed port is further provided on the top of the cleaning chamber for infusing the filtrate;

[0009] In some optional embodiments, a pressure regulating valve, an exhaust valve and a safety valve are also provided on the top of the cleaning chamber.

[0010] In some alternative embodiments, a first stirring rod is further provided in the cleaning chamber, and the stirring center is controlled in the liquid level of the low melting point metal.

[0011] In some alternative embodiments, a liquid level gauge is further provided on one side of the cleaning chamber for displaying the liquid level of the current low melting point metal.

[0012] In some alternative embodiments, the first discharge port extends a certain height into the interior of the cleaning chamber to prevent the filtrate adhering to the inner wall of the cleaning chamber from entering the pipeline through the first discharge port.

[0013] In some alternative embodiments, a second discharge port is further opened at the bottom of the cleaning chamber, which is flush with the bottom surface of the cleaning chamber and communicates with the waste liquid pool.

[0014] In some alternative embodiments, a first switching valve is provided between the second discharge port and the waste liquid pool.

[0015] In some alternative embodiments, the at least one chamber further includes a melting chamber located at the starting section of the pipeline; the melting chamber is composed of a continuous melting cavity and a heat dissipation cavity, and the melting cavity and the heat dissipation cavity are connected or shut off through a heat insulation baffle; the low melting point metal is formed in the melting cavity with a first temperature, flows through the heat dissipation cavity, and is reduced to a second temperature through the heat transfer effect of the heat dissipation cavity, and then enters the pipeline.

[0016] In some alternative embodiments, a second stirring rod is further provided in the melting cavity.

[0017] In some alternative embodiments, the low melting point metal is formed by alloy reaction of two or more metals.

[0018] In some alternative embodiments, the at least one chamber further includes a liquid storage chamber located on the pipeline after the cleaning chamber for storing the low melting point metal purified by the cleaning chamber.

[0019] In some alternative embodiments, a first flow control component is provided on the pipeline between the melting chamber and the cleaning chamber for controlling the transfer of the low melting point metal from the melting chamber to the cleaning chamber through the pipeline; a second flow control component is provided on the pipeline between the cleaning chamber and the liquid storage chamber for controlling the transfer of the low melting point metal from the cleaning chamber to the liquid storage chamber through the pipeline; a third flow control component is provided on the pipeline between the liquid storage chamber and the end section of the pipeline for controlling the transfer of the low melting point metal from the liquid storage chamber to the end section of the pipeline.

[0020] In some alternative embodiments, the first flow control component, the second flow control component, and the third flow control component are respectively composed of a flow meter, a peristaltic pump controlled by the flow meter, and a second switching valve.

[0021] In some alternative embodiments, a vacuum pump and an inert gas pressure balance component are connected to the pipeline; the vacuum pump is used to evacuate the air in the pipeline, and the inert gas pressure balance component is used to fill the pipeline with inert gas to balance the air pressure.

[0022] Another object of the present invention is to provide a low melting point metal ink filling system. Based on the structure of the above-mentioned low melting point metal ink channel, it further includes: an ink filling pipe connected to the end section of the low melting point metal ink channel; and a conveyor belt located below the ink filling pipe, used to drive the ink cartridge to move directly below the ink filling pipe; the ink filling pipe is connected to the pipeline through a hose and extends into the bottom of the ink cartridge or disengages from the ink cartridge under the drive of a vertical moving mechanism.

[0023] Another object of the present invention is to provide a low melting point metal printing system. The printing system includes the low melting point metal ink channel described in any one of the above, as the ink supply system of the low melting point metal printing system, and its end section is connected to the print head of the printing system to realize the printing operation of the print head.

[0024] Compared with the prior art, the present invention has the following advantages:

[0025] In the present invention, by using a cleaning chamber in the ink channel of the low melting point metal to remove impurities and purify the low melting point metal, the problem of reduction in the purity of the low melting point metal is prevented. Description of the Drawings

[0026] Figure 1 is a schematic structural diagram of the ink channel in an embodiment of the present invention;

[0027] Figure 2 is a schematic structural diagram of the ink filling system in an embodiment of the present invention. Detailed Embodiments

[0028] The following description and the accompanying drawings fully illustrate specific embodiments of the present invention so that those skilled in the art can practice them. Other embodiments may include structural, logical, electrical, process and other changes. The examples represent possible variations only. Unless explicitly required, separate components and functions are optional, and the order of operation may vary. Parts and features of some embodiments may be included in or replace parts and features of other embodiments. The scope of the embodiments of the present invention includes the entire scope of the claims, and all available equivalents of the claims. In this article, these embodiments of the present invention may be represented individually or collectively by the term "invention", which is merely for convenience, and if more than one invention is disclosed in fact, it is not intended to automatically limit the scope of the application to any single invention or inventive concept.

[0029] Now refer to Figure 1 In order to solve the problem that low-melting-point metal (also called liquid metal) is easily oxidized by air and thus has a reduced purity, the present invention proposes a low-melting-point metal ink channel, comprising: a pipeline 100 for conveying molten low-melting-point metal; at least one chamber arranged in the pipeline 100 and connected to the pipeline 100; at least one cleaning chamber 210 exists in the at least one chamber for removing oxygen elements in the low-melting-point metal.

[0030] Preferably, the present invention proposes a pipeline structure for cleaning low-melting-point metals, wherein the cleaning chamber 210 is connected to the pipeline 100 through a first feed port 211 and a first discharge port 212, wherein the first feed port 211 is located at the top of the cleaning chamber 210, and the first discharge port 212 is located at the bottom of the cleaning chamber 210; the cleaning chamber 210 contains a filtrate 213 floating on the surface of the low-melting-point metal, and the filtrate 213 reacts chemically with the metal oxides entrained in the low-melting-point metal 214, thereby eliminating the metal oxides. Among them, the filtrate 213 can be a 0.1mol / L-0.2mol / L sodium hydroxide solution. Since the specific gravity of the low-melting-point metal 214 is much greater than that of the sodium hydroxide solution, as the low-melting-point metal gradually enters, the metal oxides entrained in the low-melting-point metal will react chemically with the sodium hydroxide solution floating on the surface, and the pure low-melting-point metal will be deposited below the sodium hydroxide solution.

[0031] In some embodiments, the top of the cleaning chamber 210 is further provided with a second feed port 215 for injecting the filtrate 213, i.e., the sodium hydroxide solution. Preferably, the second feed port 215 is provided on one side of the cleaning chamber 210, adjacent to the inner wall of the cleaning chamber 210, to prevent the added filtrate 213 from impacting the low melting point metal.

[0032] In some embodiments, a first stirring rod 216 is further disposed in the cleaning chamber 210, and its stirring center is controlled in the liquid level of the low melting point metal 214. The cleaning chamber 210 can also provide a mode of removing impurities by rapid stirring, that is, first pouring a certain amount of low melting point metal into the cleaning chamber, then pouring a certain amount of filtering liquid, and then rapidly stirring for a period of time (such as 10 minutes) by the first stirring rod 216 to achieve sufficient reaction between the metal oxide and the filtering liquid, and then standing for a period of time (1 - 3 h) to achieve sufficient stratification between the low melting point metal and the filtering liquid. After that, the low melting point metal that has been decontaminated can be extracted.

[0033] In some embodiments, a liquid level gauge 217 is further disposed on one side of the cleaning chamber 210 for displaying the current liquid level of the low melting point metal 214. In some embodiments, a second discharge port 218 is further opened at the bottom of the cleaning chamber 210, which is flush with the bottom surface of the inner cavity of the cleaning chamber 210 and communicates with the waste liquid tank 800. A first switching valve 101 is disposed between the second discharge port 218 and the waste liquid tank 800. Since the cleaning chamber 210 will contain a small amount of filtering liquid and the waste liquid generated by the above reaction, a reference value can be set on the liquid level gauge. When the liquid level of the low melting point metal is lower than this reference value, the first discharge port 212 is controlled not to discharge the low melting point metal, so as to avoid the influence of the waste liquid on the purity of the extracted low melting point metal. At this time, the remaining liquid in the cleaning chamber 210 is discharged as waste liquid through the second discharge port 218.

[0034] In some embodiments, the bottom of the cleaning chamber 210 has an inclined surface guiding towards the second discharge port 218, which is convenient for discharging the waste liquid to the greatest extent.

[0035] In some embodiments, the first discharge port 212 extends a certain height into the cleaning chamber 210, so that the first discharge port 212 is higher than the bottom of the cleaning chamber 210, avoiding the filtering liquid adhering to the inner wall of the cleaning chamber from entering the pipeline 100 through the first discharge port 212.

[0036] In some embodiments, a pressure regulating valve 219, an exhaust valve 220 and a safety valve 221 are further disposed at the top of the cleaning chamber. Among them, the pressure regulating valve 219 is used to adjust the pressure inside the cleaning chamber 210 so that the air pressure environment inside it is always maintained consistent with the outside; the exhaust valve 220 is opened when the pressure inside the cleaning chamber 210 once reaches 1.05 times the standard atmospheric pressure; when the pressure drops, the exhaust valve 220 closes again, so as to balance the air pressure of the pipeline system. The safety valve 221 is to prevent the exhaust valve 220 from being blocked and the pressure rising too high, resulting in the danger of explosion of the cleaning chamber 210. Once the pressure exceeds the set safety pressure limit, the safety valve 221 is opened.

[0037] In some embodiments, the at least one chamber further includes a smelting chamber 240 located at the starting section of the pipeline 100; the smelting chamber 240 is composed of a continuous smelting cavity 241 and a heat dissipation cavity 242, and the smelting cavity 241 and the heat dissipation cavity 242 are connected or shut off through a heat insulation baffle 243; the low melting point metal is formed in the smelting cavity 241 having a first temperature, and is reduced to a second temperature through heat transfer by flowing through the heat dissipation cavity 242, and then enters the pipeline 100.

[0038] Preferably, the first temperature is at least 5°C higher than the melting point of the metal components constituting the low melting point metal, the second temperature is lower than the first temperature, and is at least 5°C higher than the melting point of the low melting point metal.

[0039] Among them, a third feed port 244 is provided at the upper part of the smelting cavity 241, and a heating component 245 is buried at the bottom thereof. In some embodiments, metal raw materials (which can be solid or liquid), such as one or several of gallium, indium, tin, bismuth, etc., can be input through the third feed port 244, and through the heating action of the heating component 245, a molten state is formed and an alloy reaction occurs between them. Preferably, the low melting point metal ink channel in the embodiment of the present invention can be used to transport gallium indium alloy / gallium indium tin alloy. In the eutectic state of these two metals, they can present a stable liquid state at room temperature, and there is no need to set heating components at other positions of the ink channel. The function of the heat dissipation cavity 242 is to buffer the low melting point metal flowing out of the smelting cavity 241, achieve rapid cooling, and avoid high-temperature low melting point metal from entering the temperature-intolerant pipeline and damaging the pipeline system.

[0040] Those skilled in the art should understand that in the embodiment of the present invention, the low melting point metal ink channel can also operate in a certain high-temperature environment by replacing the temperature-resistant material.

[0041] The low melting point metal in the embodiment of the present invention refers to a metal single substance or metal alloy with a melting point below 300°C. More preferably, the melting point of the low melting point metal is selected to be below 100°C. The main components of the low melting point metal can be one or several of gallium, indium, tin, bismuth, etc., and the remaining components can be one or several of zinc, cadmium, lead, silver, copper.

[0042] In some embodiments, a second stirring rod 246 is further provided in the smelting cavity 242 for sufficient alloy reaction and heat transfer between the low melting point metals.

[0043] In some embodiments, the at least one chamber further includes a liquid storage chamber 270 located on the pipeline after the cleaning chamber 210, for storing the low melting point metal purified by the cleaning chamber 210.

[0044] In some embodiments, a first flow control assembly 102 is provided on the pipeline 100 between the smelting chamber 240 and the cleaning chamber 210 for controlling the transfer of the low-melting-point metal from the smelting chamber to the cleaning chamber through the pipeline; a second flow control assembly 103 is provided on the pipeline between the cleaning chamber 210 and the liquid storage chamber 270 for controlling the transfer of the low-melting-point metal from the cleaning chamber to the liquid storage chamber through the pipeline; a third flow control assembly 104 is provided on the pipeline between the liquid storage chamber 270 and the end section of the pipeline 100 for controlling the transfer of the low-melting-point metal from the liquid storage chamber to the end section of the pipeline. Among them, the first flow control assembly 102, the second flow control assembly 103 and the third flow control assembly 104 are respectively composed of a flowmeter 105, a peristaltic pump 106 and a second switching valve 107 controlled by the flowmeter 105.

[0045] Among them, the peristaltic pump 106 and the flowmeter 105 are used in combination to accurately measure the volume and flow rate of the low-melting-point metal passing through. A closed-loop control is formed between the peristaltic pump 106 and the flowmeter 105 to continuously monitor the working condition of the peristaltic pump 106 according to the standard scale of the flowmeter 105. When the actual output flow Q0 of the peristaltic pump 106 is not equal to the initially set value Q1, the peristaltic pump 106 will automatically compensate according to the actual output flow given on the flowmeter 105 and reset the flow to Q2.

[0046] Specifically, Q2 satisfies the following formula: when Q0 > Q1, Q2 = Q1 - (Q0 - Q1); when Q0 < Q1, Q2 = Q1 + (Q1 - Q0).

[0047] In some embodiments, a vacuum pump 300 and an inert gas pressure balance assembly are connected in the pipeline; the vacuum pump 300 is used to evacuate the air in the pipeline 100, and the inert gas pressure balance assembly is used to inject inert gas into the pipeline 100 to balance the air pressure. Preferably, the inert gas pressure balance assembly is composed of a nitrogen cylinder 401 and a pressure reducing valve 402, and its function is to displace the air in the entire low-melting-point metal ink channel while evacuating the air to prevent the low-melting-point metal from oxidizing during the canning process. After the entire low-melting-point metal ink channel is filled with sodium hydroxide solution in the cleaning chamber 210, all valves need to be opened, and the pressure of the nitrogen output from the nitrogen cylinder 401 is adjusted through the pressure reducing valve 402. The pressure of the nitrogen output is one atmospheric pressure. By continuously supplying nitrogen to the low-melting-point metal ink channel for 10 minutes, after the protective gas module finishes working, all valves need to be closed in time to achieve the purpose of displacing the air in the entire low-melting-point metal ink channel.

[0048] Such as Figure 2, based on the low-melting-point metal ink channel in the above embodiments, the present invention further provides a low-melting-point metal ink filling system. This ink filling system is used to fill low-melting-point metal into individual ink cartridges through the above ink channel. Based on the structure of the above low-melting-point metal ink channel, the ink filling system further includes: an ink filling tube 500 communicated with the end section of the low-melting-point metal ink channel; and a conveyor belt 600 located below the ink filling tube, which is used to drive the ink cartridge 700 to move directly below the ink filling tube 500; the ink filling tube 500 is connected to the pipeline 100 through a hose and extends into the bottom of the ink cartridge 500 or disengages from the ink cartridge under the drive of a vertical moving mechanism to achieve ink filling.

[0049] In some preferred embodiments, the number of the ink filling tubes 500 can be multiple, which can simultaneously meet the simultaneous filling of multiple ink cartridges.

[0050] Based on the low-melting-point metal ink channel in the above embodiments, another object of the present invention is to provide a low-melting-point metal printing system. The interior of this printing system includes the low-melting-point metal ink channel described in any one of the above as the ink supply system of the low-melting-point metal printing system, and its end section is communicated with the print head of the printing system to achieve the printing operation of the print head.

[0051] Those skilled in the art should also understand that various illustrative logical blocks, modules, circuits, and algorithm steps described in conjunction with the embodiments of this article can be implemented as electronic hardware, computer software, or a combination thereof. To clearly illustrate the interchangeability between hardware and software, the above various illustrative components, blocks, modules, circuits, and steps have been generally described in terms of their functions. Whether such a function is implemented as hardware or software depends on the specific application and the design constraints imposed on the entire system. Skilled technicians can implement the described functions in a flexible manner for each specific application. However, such implementation decisions should not be construed as departing from the protection scope of the present disclosure.

Claims

1. A low-melting-point metal ink channel, characterized in that, it includes: a pipeline for transporting molten low-melting-point metal; at least one chamber arranged in the pipeline and communicated with the pipeline; at least one cleaning chamber exists in the at least one chamber, which is used to remove oxygen elements in the low-melting-point metal; the cleaning chamber is communicated with the pipeline through a first feed port and a first discharge port, the first feed port is located at the top of the cleaning chamber, and the first discharge port is located at the bottom of the cleaning chamber; a filtrate floating on the surface of the low-melting-point metal is accommodated in the cleaning chamber, and the filtrate chemically reacts with the metal oxides entrained in the low-melting-point metal.

2. The low-melting-point metal ink channel according to claim 1, characterized in that, the first discharge port extends a certain height into the interior of the cleaning chamber to prevent the filtrate adhering to the inner wall of the cleaning chamber from entering the pipeline through the first discharge port.

3. The low-melting-point metal ink channel according to claim 2, characterized in that, a second discharge port is further opened at the bottom of the cleaning chamber, which is flush with the bottom surface of the cleaning chamber and communicated with a waste liquid pool.

4. The low-melting-point metal ink channel according to claim 1, characterized in that, the at least one chamber further includes a melting chamber located at the starting section of the pipeline; the melting chamber is composed of a continuous melting cavity and a heat dissipation cavity, and the melting cavity and the heat dissipation cavity are communicated or shut off through a heat insulation baffle; the low-melting-point metal is formed in the melting cavity with a first temperature, and is reduced to a second temperature through heat transfer of flowing through the heat dissipation cavity, and then enters the pipeline.

5. The low-melting-point metal ink channel according to claim 4, characterized in that, the at least one chamber further includes a liquid storage chamber located on the pipeline after the cleaning chamber, which is used to store the low-melting-point metal purified by the cleaning chamber.

6. The low-melting-point metal ink channel according to claim 5, characterized in that, a first flow control component is arranged on the pipeline between the melting chamber and the cleaning chamber, which is used to control the transfer of the low-melting-point metal from the melting chamber to the cleaning chamber through the pipeline; a second flow control component is arranged on the pipeline between the cleaning chamber and the liquid storage chamber, which is used to control the transfer of the low-melting-point metal from the cleaning chamber to the liquid storage chamber through the pipeline; a third flow control component is arranged on the pipeline between the liquid storage chamber and the end section of the pipeline, which is used to control the transfer of the low-melting-point metal from the liquid storage chamber to the end section of the pipeline through the pipeline.

7. The low-melting-point metal ink channel according to claim 1, characterized in that, a vacuum pump and an inert gas pressure balance component are communicated in the pipeline; the vacuum pump is used to evacuate the air in the pipeline, and the inert gas pressure balance component is used to inject inert gas into the pipeline to balance the pressure.

8. A low-melting-point metal ink filling system, characterized in that, it includes the low-melting-point metal ink channel according to any one of claims 1-7; it further includes: an ink filling pipe communicated with the end section of the low-melting-point metal ink channel; and a conveyor belt located below the ink filling pipe, which is used to drive the ink cartridge to move directly below the ink filling pipe; Wherein, the ink filling pipe is connected to the pipeline through a flexible hose and extends into the bottom of the ink cartridge or disengages from the ink cartridge under the drive of the vertical moving mechanism.

9. A low melting point metal printing system, characterized in that it includes the low melting point metal ink path according to any one of claims 1-7 as the ink supply system of the low melting point metal printing system, and the end section thereof is communicated with the print head of the printing system.

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