CN116180206A

CN116180206A - Roll-to-roll equipment and method for annealing polycrystalline copper strips

Info

Publication number: CN116180206A
Application number: CN202310071870.7A
Authority: CN
Inventors: 杨军; 姜平; 孔玮
Original assignee: West Lake Yanshan Technology Hangzhou Co ltd
Current assignee: West Lake Yanshan Technology Hangzhou Co ltd
Priority date: 2023-02-07
Filing date: 2023-02-07
Publication date: 2023-05-30

Abstract

The invention belongs to the technical field of copper strip treatment, and relates to a roll-to-roll device and a roll-to-roll method for annealing polycrystalline copper strips, wherein the dynamic annealing from the polycrystalline copper strips to single crystal copper strips can be realized by controlling the temperature of each temperature zone in an annealing chamber, the annealing atmosphere and the transmission speed of the copper strips, so that hundred-meter-grade single crystal copper strips are continuously and stably produced, and the yield of the single crystal copper strips is greatly improved; the invention aims at the problem of the stress generally introduced in the roll-to-roll annealing and stretching process, and can eliminate the stress and reduce the surface roughness by adjusting the rotation speed, the positive and negative temperature gradients and the winding number of the copper strip in the second temperature zone.

Description

Roll-to-roll equipment and method for annealing polycrystalline copper strips

Technical Field

The invention belongs to the technical field of processing polycrystalline copper strips into monocrystalline copper strips, and relates to roll-to-roll equipment and a method for annealing the polycrystalline copper strips.

Background

Copper is widely used in power electronic devices as a base material of modern technology because of its excellent electrical conductivity and ultra-high thermal conductivity. Although copper reserves are abundant and excellent in performance, copper foil or electrolytic copper foil used in manufacturing industry is often polycrystalline copper foil, and the performance of copper is limited due to a large number of structural defects and crystal boundaries of the polycrystalline copper foil, while single crystal copper has few defects and no crystal boundary, so that the defects are overcome, and in addition, single crystal copper is an ideal substrate in the fields of two-dimensional materials, surface science, new energy and catalysis. For example, the monocrystal copper foil can be used as a substrate to realize uniform deposition of metal lithium so that the coulomb efficiency of the Li/Cu battery reaches 98%, and can also be used as an effective substrate and a catalyst for growing graphene, thereby obtaining a high-quality graphene sample. These reasons have made single crystal copper materials the subject of industry competitive growth.

However, the current-stage single crystal copper acquisition mainly depends on annealing of the polycrystalline copper strip, and mainly faces the following problems: (1) The annealing size is mostly in the order of centimeters, the acquisition area is limited, and static annealing is mostly adopted, the annealing period is long, and the production efficiency of equipment is low.

(2) The annealing process often requires traction through mechanical actuators, thus introducing stresses that degrade its performance.

(3) The surface roughness after annealing can be obviously reduced compared with that before annealing, but still is in the hundred-nanometer or micrometer level, which is not beneficial to the processing design of subsequent devices.

Therefore, it is important to develop an apparatus and method for producing single crystal copper with reduced surface roughness and with reduced stress.

The roll-to-roll equipment is a production field which is developed rapidly in recent years and can be applied to flexible solar batteries, lithium batteries, superconducting wires, graphene and the like, and can realize batch growth of products; aiming at the difficult problems faced by the copper industry, the invention can realize hundred-meter-grade polycrystalline copper strip annealing by designing a set of roll-to-roll system, and high-quality monocrystalline copper strips can be produced efficiently.

Disclosure of Invention

In order to solve the technical problems in the prior art, the invention provides roll-to-roll equipment and a method for annealing a polycrystalline copper strip, and the specific technical scheme is as follows:

a roll-to-roll equipment for annealing polycrystalline copper strips comprises an unreeling chamber, an annealing chamber, a reeling chamber and a transmission system for controlling the copper strips to be transported in the unreeling chamber, the annealing chamber and the reeling chamber; the transmission system comprises an unreeling device positioned in the unreeling chamber, a rotating device positioned in the annealing chamber and a reeling device positioned in the reeling chamber; the unreeling device comprises a first reel, an unreeling roller, a first tension wheel and a first guide roller; the winding device comprises a second reel, a winding roller, a second tension wheel and a second guide roller.

Preferably, the annealing chamber is divided into a first temperature zone, a second temperature zone and a third temperature zone by setting different temperature gradients and lengths; the first reel is arranged on the unreeling roller, a polycrystalline copper strip is placed and is wound with the polycrystalline copper strip, the polycrystalline copper strip is sequentially conveyed to the annealing chamber through the first tension roller and the first guide roller, enters the first temperature zone through the inlet of the annealing chamber, is then conveyed and wound on the rotating device positioned in the second temperature zone and is converted into a monocrystalline copper strip, the monocrystalline copper strip is then conveyed to the third temperature zone through the rotating device to finish stress release of the copper strip, is then conveyed to the reeling chamber through the outlet of the annealing chamber, and finally sequentially passes through the second guide roller and the second tension roller in the reeling chamber, and is then wound on the second reel arranged on the reeling roller.

Preferably, the heating mode in the annealing chamber is as follows: the annealing chamber is heated outside and then reaches the copper strip sample through radiation heat transfer.

Preferably, the temperature of the first temperature region is 1040-1060 ℃, the length of the first temperature region is 10cm, and the polycrystalline copper strips migrate at the grain boundary of the first temperature region.

Preferably, the temperature of the second temperature zone is 1010-1030 ℃, and the polycrystalline copper strips are combined in a crystal boundary way, so that the polycrystalline copper is converted into single crystal copper, and the single crystal copper strips are formed;

the temperature of the first temperature zone is higher than that of the second temperature zone, a negative temperature gradient is formed, grain boundary migration is facilitated, and the temperature gradient is guaranteed to be 3-5 ℃/cm.

Preferably, the temperature of the third temperature zone is 1060-1080 ℃, and the length of the third temperature zone is 20cm.

The temperature of the third temperature zone is higher than that of the second temperature zone, a positive temperature gradient is formed, and the temperature gradient is ensured to be 4-8/DEGC/cm.

Preferably, the rotating device is cylindrical as a whole and rotates through a rotating shaft arranged at the center.

Preferably, the outer wall of the rotating device and the annealing chamber are made of high-purity quartz materials.

The annealing method of the polycrystalline copper strip comprises the following steps:

winding a polycrystalline copper strip with the width of 5cm onto a first reel, and then installing the first reel on which the polycrystalline copper strip is wound at the position of an unreeling roller;

step two, leading out the polycrystalline copper strips from the unreeling roller, sequentially passing through a first tension wheel, a first guide roller and an annealing chamber inlet to enter a first temperature zone of the annealing chamber, wherein the temperature of the first temperature zone is 1040-1060 ℃, the length of the first temperature zone is 10cm, and the polycrystalline copper strips complete grain boundary migration in the first temperature zone and then enter a second temperature zone;

step three, the temperature of the second temperature region is 1010-1030 ℃, the polycrystalline copper strips after the crystal boundary migration of the first temperature region are wound on the outer wall of the rotating device for 5 circles, crystal boundary combination is completed, the polycrystalline copper strips are converted into single-crystal copper strips, and the polycrystalline copper strips are wound on the rotating device for many times, so that the annealing efficiency is improved, and the annealing period is shortened; then continuously conveying the material into a third temperature zone, wherein the temperature of the third temperature zone is 1060-1080 ℃, and the length of the temperature zone is 20cm, so as to finish stress release; the temperature is a high temperature region and is close to the melting point of copper, so that stress release and atom migration are facilitated, the quality of single crystals is improved, and the surface roughness is reduced;

and step four, the monocrystalline copper strip is transmitted out through an outlet of the annealing chamber, is wound on a second reel arranged on the winding roller through a second guide roller and a second tension wheel, and completes the complete annealing process of the polycrystalline copper strip.

Preferably, the annealing chamber is in a vacuum state, and a process gas is introduced, wherein the process gas comprises: ar and H2, wherein the Ar flow is 100-600 sccm, and H2 is 50-200 sccm; wherein the moving speed of the copper strip is 0.4-1 cm/min.

Advantageous effects

The roll-to-roll copper strip annealing equipment has simple structure, low cost and simple operation, can produce hundred-meter-level single crystal copper strips in batches, and is beneficial to solving the problems of small static annealing single crystal area and long annealing period; meanwhile, the problem of stress caused by stretching in the dynamic annealing process is properly solved, the stress is released through a positive temperature gradient annealing process, the crystal quality of the copper strip is improved, the surface roughness is greatly reduced, and the processing and performance improvement of a later device are facilitated.

Drawings

FIG. 1 is a schematic cross-sectional view of the overall structure of a roll-to-roll apparatus for annealing polycrystalline copper strips of the present invention;

FIG. 2 is a schematic view of Electron Back Scattering (EBSD) of a single crystal copper strip obtained in example 1 of the present invention, showing that the single crystal copper strip sample has a Cu (111) crystal orientation;

FIG. 3 is a graph showing the swing curve of the single crystal copper strip Cu (111) obtained in example 1 in X-ray direction;

FIG. 4 is a graph showing the characterization result of the surface roughness of the single crystal copper strip in the embodiment 2 by an Atomic Force Microscope (AFM);

in the figure, 1-a first tension wheel; 2-polycrystalline copper strips; 3-a first guide roller; 4-unreeling rollers; 5-annealing chamber inlet; 6-a first temperature zone; 7-rotating means; 8-rotating shaft; 9-a second temperature zone; 10-a third temperature zone; 11-an annealing chamber outlet; 12-a wind-up roll; 13-a second guide roller; 14-monocrystalline copper strips; 15-a second tension pulley.

Description of the embodiments

In order to better understand the technical solutions in the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below, and it is obvious that the described embodiments are only some embodiments of the present application, not all embodiments. All other embodiments, which can be made by one of ordinary skill in the art without undue burden from the present disclosure, are within the scope of the present disclosure.

It is noted that when an element is referred to as being "fixed," "mounted," or "disposed" on another element, it can be directly on the other element or be indirectly disposed on the other element; when an element is "connected" or "connected" to another element, it can be directly connected or indirectly connected to the other element.

It is to be understood that the terms "length," "width," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," and the like indicate or are based on the orientation or positional relationship shown in the drawings, merely to facilitate description of the present application and simplify description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be configured and operated in a particular orientation, and therefore should not be construed as limiting the present application.

Furthermore, the terms "first," "second," and the like, are used for descriptive purposes only and are not to be construed as indicating or implying a relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include one or more such feature. In the description of the present application, the meaning of "a plurality" or "a number" is two or more, unless explicitly defined otherwise.

It should be understood that the structures, proportions, sizes, etc. shown in the drawings are for illustration purposes only and should not be construed as limiting the scope of the present disclosure, since any structural modifications, proportional changes, or dimensional adjustments made by those skilled in the art should not be made in the present disclosure without affecting the efficacy or achievement of the present disclosure.

As shown in fig. 1, the roll-to-roll equipment for annealing the polycrystalline copper strips is provided with an unreeling chamber, an annealing chamber and a reeling chamber, and a transmission system for controlling the copper strips to be cooperatively transported in the unreeling chamber, the annealing chamber and the reeling chamber; the transmission system comprises an unreeling device positioned in the unreeling chamber, a rotating device 7 positioned in the annealing chamber and a reeling device positioned in the reeling chamber; the unreeling device comprises a first reel, an unreeling roller 4, a first tension wheel 1 and a first guide roller 3; the winding device comprises a second reel, a winding roller 12, a second tension wheel 15 and a second guide roller 13; the annealing chamber is divided into a first temperature zone 6, a second temperature zone 9 and a third temperature zone 10 by setting different temperatures and lengths.

The heating mode in the annealing chamber is as follows: the outside of the annealing chamber is heated and then reaches the copper strip sample through radiation heat transfer.

The first reel is arranged on the unreeling roller 4 and used for winding and supplying the polycrystalline copper strips 2, the polycrystalline copper strips with a certain length are placed on the first reel, the polycrystalline copper strips 2 are sequentially conveyed to an annealing chamber through the first tension wheel 1 and the first guide roller 3, enter a first temperature zone 6 through an inlet of the annealing chamber, the temperature of the first temperature zone 6 is 1040-1060 ℃, the length of the first temperature zone 6 is 10cm, grain boundary migration of the polycrystalline copper strips 2 is achieved in the zone under a temperature gradient, and then the polycrystalline copper strips are conveyed and wound on a rotating device 7 located in a second temperature zone 9.

The rotating device 7 is integrally cylindrical and has a certain length and diameter, the rotating device rotates through a rotating shaft 8 arranged in the center, the copper strip is wound after the winding number of the copper strip is set on the outer wall of the rotating device 7 according to the process requirement, and the winding number of the copper strip is related to the movement speed of the copper strip. The rotating device 7 is designed to prevent the copper strip from deformation and stretch-breaking at high temperature and reduce friction force in the copper strip transmission process.

The outer wall of the rotating device 7 and the annealing chamber are made of high-purity quartz materials, and a clean environment is provided to ensure the cleanness of the copper surface.

The temperature of the second temperature zone 9 is 1010-1030 ℃, grain boundary combination is completed on the polycrystalline copper strip in the temperature zone, the polycrystalline copper strip is converted into a single crystal copper strip 14, then the single crystal copper strip is transmitted to the third temperature zone 10, and is transmitted to a winding chamber through an annealing chamber outlet 11, and sequentially passes through a second guide roller 13 and a second tension wheel 15 in the winding chamber, and then is wound and collected on a second reel arranged on the winding roller 12.

The temperature of the third temperature region 10 is 1060-1080 ℃, and the length of the third temperature region 10 is 20cm. The single crystal copper strip will achieve stress relief in this high temperature region to improve crystal quality and reduce surface roughness by high temperature atomic diffusion migration.

Examples

The roll-to-roll equipment for annealing the polycrystalline copper strip is used for annealing the polycrystalline copper strip, and specifically comprises the following steps of:

winding a polycrystalline copper strip 2 with the width of 5cm onto a first reel, and then installing the first reel wound with the polycrystalline copper strip 2 at the position of an unreeling roller 4;

step two, the polycrystalline copper strip 2 is led out from the unreeling roller 4, sequentially passes through the first tension wheel 1, the first guide roller 3 and the annealing chamber inlet 5 and enters the first temperature zone 6, the temperature of the first temperature zone 6 is 1040 ℃, the length of the first temperature zone 6 is 10cm, and the polycrystalline copper strip 2 realizes grain boundary migration under the driving of the temperature gradient of the zone and then enters the second temperature zone 9;

step three, the temperature of the second temperature area 9 is 1020 ℃, the polycrystalline copper strips 2 are wound 5 circles on the outer wall of the rotating device 7 after passing through the first temperature area 6, grain boundary combination is realized, so that the polycrystalline copper is converted into single crystal copper strips 14, then the single crystal copper strips are continuously conveyed into a third temperature area 10 to finish stress release, the temperature of the third temperature area 10 is 1070 ℃, and the length of the temperature area is 20cm;

and step four, the monocrystalline copper strips 14 are conveyed out through an annealing chamber outlet 11 and are wound on a second reel arranged on a winding roller 12 through a second guide roller 13 and a second tension wheel 15, so that the annealing process of the polycrystalline copper strips 2 is completed.

The annealing chamber is in a vacuum state, and is filled with process gas, wherein the process gas comprises the following components: ar and H2 mixed gas, wherein Ar is 300 sccm, and H2 is 100sccm.

The moving speed of the copper belt is 1cm/min.

Fig. 2 is a schematic view of Electron Back Scattering (EBSD) of the single crystal copper strip obtained in this example 1, showing that the single crystal copper strip sample is Cu (111) crystal orientation, indicating good single orientation.

FIG. 3 is a graph showing the X-ray rocking curve in the Cu (111) direction of the single-crystal copper strip obtained in example 1, wherein the half-width is 0.214 degrees, which shows that the crystal quality of the single-crystal copper strip is better.

Examples

The roll-to-roll equipment for annealing the polycrystalline copper strips is used for carrying out vacuum annealing on the polycrystalline copper strips, and specifically comprises the following steps of:

step two, the polycrystalline copper strips 2 are led out from the unreeling roller 4 and enter the annealing chamber through the first tension wheel 1, the first guide roller 3 and the annealing chamber inlet 5 in sequence;

step three, vacuumizing the annealing chamber, checking the air tightness, and then introducing process gas, such as: ar, H2, etc.; wherein the temperature of the first temperature zone 6 is 1060 ℃, the length of the temperature zone is 10cm, the polycrystalline copper strip realizes grain boundary migration under the temperature gradient, and then enters the second temperature zone 9; the temperature of the second temperature zone 9 is 1010 ℃, the polycrystalline copper strips 2 after seed crystal growth in the first temperature zone 6 are wound 5 circles on the outer wall of the rotating device 7, grain boundary combination is realized, the polycrystalline copper strips 2 are converted into monocrystalline copper strips 14, and then the monocrystalline copper strips are continuously conveyed into the third temperature zone 10 to finish stress release; the temperature of the third temperature zone 10 is 1080 ℃, and the length of the temperature zone is 20cm;

The annealing chamber is in a vacuum state, and is filled with process gas, wherein the process gas comprises the following components: ar and H2 mixed gas, wherein Ar is 500 sccm, and H2 is 200sccm.

The moving speed of the copper belt is 0.5 cm/min.

FIG. 4 shows the AFM test results (test range 5 μm. Times.5 μm) of the single crystal copper strip obtained in example 2, with a surface roughness RMS of about 1nm, indicating that a very flat copper strip surface can be achieved by the annealing method of the present invention.

In conclusion, the roll-to-roll equipment provided by the invention has a simple structure, the dynamic annealing from polycrystalline copper to monocrystalline copper can be completed by controlling the temperature of each temperature zone in the annealing chamber, the annealing atmosphere and the transmission speed of the copper strip, the efficient and stable production of the monocrystalline copper strip is realized, the tensile stress in the annealing process can be effectively released, the roughness of the surface of the copper strip is reduced, the quality of the monocrystalline copper is improved, and a foundation is laid for the subsequent copper device processing.

Claims

1. The roll-to-roll equipment for annealing the polycrystalline copper strips is characterized by comprising an unreeling chamber, an annealing chamber, a reeling chamber and a transmission system for controlling the copper strips to be transported in the unreeling chamber, the annealing chamber and the reeling chamber; the transmission system comprises an unreeling device positioned in the unreeling chamber, a rotating device (7) positioned in the annealing chamber and a reeling device positioned in the reeling chamber; the unreeling device comprises a first reel, an unreeling roller (4), a first tension wheel (1) and a first guide roller (3); the winding device comprises a second reel, a winding roller (12), a second tension wheel (15) and a second guide roller (13).

2. A roll-to-roll apparatus for annealing of polycrystalline copper strips according to claim 1, characterized in that the annealing chamber is divided into a first temperature zone (6), a second temperature zone (9) and a third temperature zone (10) by setting different temperature gradients and lengths; the first reel is arranged on the unreeling roller (4), a polycrystalline copper strip is placed and is coiled with the polycrystalline copper strip (2), the polycrystalline copper strip (2) is sequentially conveyed to an annealing chamber through a first tension wheel (1) and a first guide roller (3), enters a first temperature zone (6) through an annealing chamber inlet (5), is then conveyed and coiled on a rotating device (7) positioned in a second temperature zone (9) and is converted into a monocrystalline copper strip (14), then is rotated and conveyed to a third temperature zone (10) through the rotating device (7), copper strip stress release is completed, is then conveyed out to a reeling chamber through an annealing chamber outlet (11), and finally sequentially passes through a second guide roller (13) and a second tension wheel (15) in the reeling chamber, and is then coiled on a second reel arranged on the reeling roller (12).

3. A roll-to-roll apparatus for annealing polycrystalline copper strips as claimed in claim 2 wherein the heating means in said annealing chamber is: the annealing chamber is heated outside and then reaches the copper strip sample through radiation heat transfer.

4. The roll-to-roll equipment for annealing of polycrystalline copper strips according to claim 2, characterized in that the temperature of the first temperature zone (6) is 1040-1060 ℃, the length of the first temperature zone (6) is 10cm, and the polycrystalline copper strips (2) migrate at the grain boundaries of the first temperature zone (6).

5. A roll-to-roll apparatus for annealing of polycrystalline copper strips according to claim 2, characterized in that the temperature of the second temperature zone (9) is 1010-1030 ℃, the polycrystalline copper strips complete grain boundary consolidation, the polycrystalline copper is converted into single crystal copper, forming single crystal copper strips (14).

6. A roll-to-roll apparatus for annealing of multicrystalline copper strips according to claim 2, characterized in that the temperature of the third temperature zone (10) is 1060-1080 ℃, the stress relief of the monocrystalline copper strips is accomplished in this temperature zone, and the length of the third temperature zone (10) is 20cm.

7. A roll-to-roll apparatus for annealing polycrystalline copper strips according to claim 1, characterized in that the rotating means (7) are entirely cylindrical and are rotated by a centrally arranged spindle (8).

8. A roll-to-roll apparatus for annealing polycrystalline copper strips according to claim 1, characterized in that the outer wall of the rotating means (7) and the annealing chamber are both made of high purity quartz material.

9. A method of annealing a polycrystalline copper strip using a roll-to-roll apparatus as claimed in any one of claims 1 to 8, comprising the steps of:

winding a polycrystalline copper strip (2) with the width of 5-10 cm onto a first reel, and then installing the first reel wound with the polycrystalline copper strip (2) at the position of an unreeling roller (4);

step two, the polycrystalline copper strip (2) is led out from the unreeling roller (4), sequentially passes through the first tension wheel (1), the first guide roller (3) and the annealing chamber inlet (5) and enters a first temperature zone (6) of the annealing chamber, the temperature of the first temperature zone (6) is 1040-1060 ℃, the length of the first temperature zone (6) is 10cm, and the polycrystalline copper strip (2) migrates in a grain boundary of the first temperature zone and then enters a second temperature zone (9);

step three, the temperature of the second temperature region (9) is 1010-1030 ℃, after the crystal boundary migration of the first temperature region (6), the polycrystalline copper strips (2) are wound on the outer wall of the rotating device (7), crystal boundary combination is completed through annealing, the polycrystalline copper strips (2) are converted into monocrystalline copper strips (14), and then the monocrystalline copper strips are continuously conveyed into a third temperature region (10) to complete stress release, wherein the temperature of the third temperature region (10) is 1060-1080 ℃, and the length of the temperature region is 20cm;

and step four, the monocrystalline copper strip (14) is conveyed out through an annealing chamber outlet (11), is wound on a second reel arranged on a winding roller (12) through a second guide roller (13) and a second tension wheel (15), and finally finishes the annealing process of the polycrystalline copper strip (2).

10. The method of annealing a polycrystalline copper strip according to claim 9, wherein the annealing chamber is vacuum filled with a process gas comprising: ar and H2, wherein the Ar flow is 100-600 sccm, and H2 is 50-200 sccm;

wherein the moving speed of the copper strip is 0.4-1 cm/min.