CN101086614B - Micrometer-class three-dimensional rolling die and its production method - Google Patents

Abstract

The rolling mold metal roller structure with the inner radius and the outside radius embedded with electric resistance heater, outside radius of the roller formed into micrometer or submillimeter three dimensional rolling figure with the cross section dimension combination as follows: min width of the cross section: L<50 mu m, depth: 0<H<500 mu m, oblique angle: 90 DEG< alpha <120 DEG, with the rolling figure coated by a thin film. Through adjusting the laser output energy and mechanical shutter action, it directly sinters millimeter and submiliter three dimensional figures on the metal mold,using the plating film machine depositing the carbon atom to millimeter or submilimeter to form the analog diamond transitional thin film in nanometer level.

Description

A three-dimensional rolling mold with micron-scale features and its manufacturing method

technical field

The invention belongs to the field of micromanufacturing technology, and in particular relates to a three-dimensional rolling die structure with large-area micron-level features and a manufacturing method thereof. The micron-level three-dimensional rolling die is mainly used for three-dimensional barrier structures and various Thermal embossing of electrodes on the upper and lower substrates of flat panel display devices, three-dimensional channel structures of large-area microfluidic devices (such as fuel cell cathode and anode plates), three-dimensional components in array microelectromechanical sensors, and three-dimensional components in array microactuation devices make.

Background technique

In the traditional micro-manufacturing technology, for the production of micron-scale (ie, less than 100 μm) feature size devices, the conventional integrated circuit photolithography production process (ie, glue + exposure + development + cleaning + chemical/physical etching, etc.) is currently mainly used. ). Its production features are limited in that the production area is limited (up to a dozen inches), the aspect ratio is small, and it needs to be completed with the cooperation of multiple continuous processes. For the manufacture of small-area (inch-level) and high-aspect-ratio structural devices, the LIGA process is currently the most promising and widely used technology, which is characterized by deep exposure on SU8 photoresist (using X-ray exposure) A straight-wall exposure area with a large depth is formed, and components with a micron-scale large aspect ratio (up to 20:1 or more) are produced through development, electroforming and other manufacturing processes. If the lift-off process is combined with the lift-off process, the fabrication of a device with a suspended bottom (such as a cantilever beam structure) can also be realized. The common features of the above two types of processes are the need for expensive exposure beam sources, special photoresist materials, precise etching (wet, dry) control, long production cycle, high cost, and the lack of ability to produce large-area (Length up to meter level or above) the ability of fine structure.

With the development of large-area plasma flat-panel displays, various flat-panel display devices, large-area microfluidic devices, array microelectromechanical sensors, and array microactuation devices, their internal structural features are not only required to be smaller and smaller in scale ( As small as the micron level), and the consistency requirements of its feature structure in a large area are getting higher and higher. The above-mentioned conventional processes are not very adaptable to these requirements, especially for large-area micron-scale three-dimensional structural features. In addition to cost issues, there are also great difficulties in technical implementation.

In the imprinting process that has emerged in recent years, the feature scale of the imprinted replica can be as small as 6nm. However, the published imprinting processes all use flat-plate molds and carry out imprinting in partitions, the area is limited, the efficiency is low, and there are no precedents or patent records for large-area (above meter level) three-dimensional microstructure imprinting attempts.

In short, micro-manufacturing usually adopts integrated circuit manufacturing technology (deep sub-micron-level features, aspect ratio of about 1:1), LIGA or quasi-LIGA in micro-electromechanical fabrication (micron-level features, aspect ratio of 20:1). The above) process is mainly determined according to the characteristic scale of the fabricated device. Their common features are that the fabricated micro-devices have a simple structure (that is, the bottom surface, top surface, and side walls of the characteristic structure are straight and planar), small in area, and have clear restrictions on the types of materials to be fabricated (such as exposure materials , base material), and the production process must be coordinated through multiple processes. For current large-area and complex three-dimensional microstructure device requirements (for example, large-area plasma flat panel displays, various flat panel display devices, large-area microfluidic devices, array microelectromechanical sensors, array microactuation devices, etc.) However, the existing technology still has difficulties such as high production cost and complicated technology.

Contents of the invention

Due to the existing etching methods, material cutting methods, and the photolithography process of the above-mentioned integrated circuits, it is impossible to directly generate micron-scale graphic structures on the cylindrical surface, let alone form a three-dimensional microstructure graphic outline. The purpose of the present invention is to provide a three-dimensional rolling die of micron-scale microstructure and its manufacturing method, which can solve the problem of large-area and complex three-dimensional microstructure devices (such as large-area plasma flat panel displays, various flat panel display devices) , large-area microfluidic devices, array microelectromechanical sensors, array microactuation devices, etc.), adopt the three-dimensional rolling mold with micron-level characteristic structure of the present invention to realize large-area three-dimensional The rolling replica of microstructure devices can greatly improve the production efficiency.

In order to realize above-mentioned task, the present invention takes following technical solution:

A three-dimensional rolling mold with micron-scale features, the rolling mold is a roller structure, and a resistance heater is embedded between the inner diameter and the outer diameter of the roller. , until sintering on the outer diameter surface of the drum mold to form a laser sintering space region with a three-dimensional curved surface boundary, and the laser sintering space region finally forms a rolling pattern with a micron to submillimeter three-dimensional structure, and there is a diamond-like transition film layer on the rolling pattern , the size combination of the structural section of the three-dimensional features of the rolling pattern is: the minimum width of the section: L<50μm, the depth: 0<H<500μm, the inclination angle: 90°<α<120°, and the rolling pattern is covered by a layer of diamond-like carbon covered by a transition film.

The method for making the above-mentioned micron-scale three-dimensional feature rolling mold is characterized in that it includes the following steps:

First build a mold making platform, which includes:

A moving platform in one direction, which can realize translation in a straight line and rotation around a straight line, and is controlled by a computer;

The moving platform is provided with a guide rail, a lead screw and a slider that drives the guide rail to perform linear motion. A connecting plate is placed on the slider, and the two ends of the connecting plate are respectively supported by a motor and a bearing. There is a rotating motor on the motor support. The motor and the bearing support are used together to install the roller mold to be processed;

A laser fixing bracket is arranged next to the moving platform, and a laser is installed on the laser fixing bracket. The laser is also controlled by a computer. A laser focusing system is installed on the optical path of the laser. Mechanical shutter, vacuum slag discharge conduit and gas protection pipeline;

Install the roller mold on the rotating motor and the bearing support, adjust the focusing device of the laser, so that the spot focused on the surface of the roller mold to be processed is in micron size, and start processing when the output power of the laser is stable;

The laser beam emitted by the laser enters the laser focusing system; the laser beam coming out of the laser focusing system passes through the mechanical shutter and is directly sintered on the surface of the drum mold to form a microstructure pattern under the protective gas introduced into the gas protection pipeline; The microstructure pattern is a three-dimensional structure with micron-level feature size. The residue formed during the laser beam sintering process is taken away by the vacuum slag discharge conduit. The output power of the laser and the movement speed of the mold making platform are controlled in real time by the computer, and the laser beam is controlled. The processing depth can realize the processing of any characteristic curve shape on the mold surface;

For the mold surface that does not need to be processed, close the mechanical shutter. At this time, the laser beam is out of focus and will not cause damage to the drum mold material to be processed. After the predetermined processing surface moves to the processing position, the mechanical shutter opens. Continue to carry out laser processing until the laser sintering space area of the three-dimensional curved surface boundary is sintered on the outer diameter surface of the drum mold, and the laser sintering space area finally forms a rolling pattern with a micron to submillimeter three-dimensional structure. The three-dimensional features of the rolling pattern The size combination of the structural section is: the minimum width of the section: L<50μm, the depth: 0<H<500μm, the inclination angle: 90°<α<120°:

Finally, a coating machine is used to deposit carbon atoms on the surface of the rolling pattern with a micron-scale to submillimeter-scale three-dimensional structure to form a diamond-like transition layer film with a thickness of nanometers, and a resistive heater is embedded between the inner and outer diameters of the roller mold.

The three-dimensional rolling mold with micron-level features of the present invention relies on the hot stamping process, and its manufacturing scale for micro-device structures includes micron-level and submillimeter-level, and adopts ultra-fast lasers with controllable power to form values directly on metal rollers. Exposure depth in the z direction as a function of χ, θ _x position, vapor deposition of a diamond-like transition layer, and finally forming a metal rolling mold with a three-dimensional structure of micron-scale features. The complexity of the cross-sectional profile of the mold surface microstructure can be set arbitrarily, which cannot be achieved economically by other conventional processes.

In the present invention, after the three-dimensional characteristic structure is formed on the metal mold body, the diamond-like transition layer evaporated on the surface of the mold is very important for changing the physical and chemical properties of the microstructure surface of the metal mold. The transition layer will be attached to the surface of the metal mold, endowing the mold with self-lubricating properties, corrosion resistance, wear resistance and moderate surface hardness. Self-lubrication has the effect of release agent on the separation of the rolling die from the thermoplastic or thermosetting processed material during the production process. The diamond-like transition layer is used as the actual surface in production, and its corrosion resistance acts as a protective layer in the cleaning of metal molds (acid-base solution); wear resistance and high surface hardness can reduce the micron-scale three-dimensional structure in the rolling process. Wear and deformation, thereby improving the service life of the rolling die.

Description of drawings

Figure 1 is a schematic diagram of the construction of a three-dimensional rolling mold manufacturing platform with micron-level features;

Figure 2 shows the working status of the gas protection and slag discharge system during the mold processing process;

Fig. 3 (a) is a schematic diagram of the processing line splicing process adopted for realizing the predetermined processing line width when processing the mould; Fig. 3 (b) is a schematic diagram of the processing line splicing process adopted for realizing the predetermined processing depth;

Fig. 4 is a schematic diagram of the processing route and corresponding processing features of the laser processing on the surface of the rolling mold;

Fig. 5 is the schematic diagram of the mold structure after the vapor deposition diamond-like transition layer on the surface of the rolling mold is completed;

Fig. 6 is a schematic diagram of the mold degumming process and the process of rolling the mold to produce large-area microstructure features.

The symbols in the figure represent respectively: 1. Laser fixing bracket; 2. Laser; 3. Laser power control card; 4. Computer; 5. Master control card; 6. Mold movement platform control card; 7. X direction movement platform; 8 , guide rail and lead screw; 9, motor; 10, roller mold; 11, microstructure graphics on the mold; 12, motor support; 13, connecting plate; 14, slider; 15, laser focusing system; 16, laser beam; 17. Bearing support; 18. Control card connection; 19. Gas protection pipeline; 20. Vacuum slag discharge conduit; 21. Mechanical shutter; 22. Protective gas; 23. Waste residue; 24. Microstructure processed by laser; 25. Processing direction; 26. Processing pattern in depth direction of microstructure; 27. Resistive heater; 28. Mold inner cavity; 29. Diamond-like film; 30. Thermosetting anti-corrosion adhesive; 31. Substrate.

The manufacturing method of the present invention will be further described in detail below in conjunction with the accompanying drawings.

Detailed ways

See attached picture. Figures 1 to 5 respectively show the schematic diagrams of the manufacturing process of the micron-scale to submillimeter-scale three-dimensional structure rolling mold.

A three-dimensional rolling mold with micron-level features, the rolling mold is a roller structure, a resistive heater 27 is embedded between the inner diameter and outer diameter of the roller, and a micron-to-submillimeter-level three-dimensional structure is formed on the surface of the outer diameter of the roller The rolling pattern of the rolling pattern, the size combination of the structural section of the three-dimensional feature of the rolling pattern is: the minimum width of the section: L<50μm, the depth: 0<H<500μm, the inclination angle: 90°<α<120°, the rolling pattern is Covered by a layer of diamond-like transition film.

The three-dimensional rolling mold of the above-mentioned micron-scale features is made according to the following steps:

(1) First build a mold making platform. The mold making platform includes:

A motion platform 7, the motion platform 7 can realize translation in the x direction and a rotation θ _x around the x direction, the motion platform 7 is connected to the mold motion platform control card 6 through the control card connection 18, and the mold motion platform control card 6 passes through the control card Connection 18 links to each other with total control card 5, and total control card 5 is connected with computer 4 through control card connection 18;

Guide rail and leading screw 8 are arranged on described motion platform 7, and slide block 14 is housed on guide rail and leading screw 8, is used for supporting the connecting plate 13 of translation and rotation, and the two ends of connecting plate 13 of translation and rotation have motor respectively Support 12 and bearing support 17, there is rotating motor 9 on motor support 12, and rotating motor 9 and bearing supporting 17 are used for installing to-be-processed drum mold 10;

Next to the moving platform 7, a laser fixing bracket 1 is arranged, and a laser 2 is arranged on the laser fixing bracket 1. One end of the laser 2 is connected to the main control card 5 through a laser power control card 3 and its control card connection line 18, and the main control card 5. The computer control system 4 is connected through the control card connection 18; the other end of the laser 2 has a laser focusing system 15, and the laser beam 16 from the laser focusing system 15 has a mechanical shutter 21 and a vacuum slag discharge conduit 20 on both sides. And gas protection pipeline 19.

The laser 2 emitted enters the laser focusing system 15; the laser beam 16 from the laser focusing system 15 passes through the mechanical shutter 21 under the protective gas 22 passed in the gas protection pipeline 19, directly on the drum mold 10 to be processed. The surface of the microstructure is sintered to form a microstructure pattern; the microstructure pattern is a three-dimensional structure with a micron-scale characteristic size, and the residue formed during the sintering process of the laser beam 16 is taken away by the vacuum slag discharge conduit 20 .

Laser 2 adopts a high-power ultrafast laser. The laser focusing system and the mold motion control platform are controlled by a computer, which makes the output power of the laser focusing system controllable. The mold motion control platform can realize the translation of the mold in the x direction and the rotation around the x direction. θ _x ;

(2) Debugging of laser 2. The focusing device of the laser 2 is adjusted so that the light spot focused on the roller mold 10 is as small as possible (micron order), so as to realize micromachining with small size and flat section.

(3) Start processing. After the output power of the laser 2 stabilizes, the processing starts. Real-time control of the output power of the laser 2 and the motion speed of the mold motion platform by the computer 4 can control the depth of laser processing; real-time control of the translation of the mold motion platform and the rotation speed of the motor 9 by the computer 4 can realize the surface of the roller mold. Processing of characteristic graphics of any curved shape; for the surface of the roller mold that does not need to be processed, the mechanical shutter 21 can be closed (at this time, the laser beam is in a defocused state and will not cause damage to the roller mold material), and the predetermined processing surface movement After arriving at the processing position, the shutter is opened to continue laser processing;

(4) During processing, since the spot of the laser beam can be focused to 1 micron, when processing features with a line width of more than tens of microns, it is necessary to splice the processing lines, which requires calculating the width of the splicing and the required width of each feature. the number of scan lines. When processing features with different line widths on the surface of the mold, real-time control of the splicing width and the number of scanning lines is required;

(5) Since increased heat is inevitably generated on the surface of the mold during laser processing, the mold must be protected by gas to avoid corrosion by oxygen in the air; for ordinary high-power lasers, vacuum must be used during processing The slag discharge conduit 20 performs slag discharge treatment to prevent waste slag from accumulating in the processed micro-feature graphics and affecting further laser processing;

(6) After the processing is completed, the surface treatment of the drum mold 10 is carried out. Firstly, the drum mold 10 is cleaned to remove the waste slag 23 adhered to the side walls and edges of the microstructure characteristic graphics; then the surface of the drum mold is coated: carbon atoms are deposited on the surface of the three-dimensional microstructure graphics 11 with micron-scale features by a coating machine On the surface, a diamond-like transition layer film 29 with a thickness of nanometer scale is formed. The material of the roller mold should have good thermal conductivity, and a resistance heater 27 is housed inside, which can realize heating during the rolling process (that is, the production process).

The size combination of the structural section of the three-dimensional feature of the rolling pattern formed by the above method is as follows: the inclination angle range of the structural section of the rolling pattern is 90°<α<120°, the lateral dimension range is L<50 μm, and the longitudinal depth range is 0<H<500 μm.

The basic working principle of the three-dimensional rolling mold with micron-level characteristics of the present invention is: through continuous rotation rolling and applying a certain pressure, and heating by a resistance heater in the rolling mold, the surface of the mold is rolled and rotated by the rolling mold. The three-dimensional microstructure pattern is thermally printed on the thermosetting corrosion-resistant adhesive 30 on the surface of any thermoplastic or thermosetting material to be processed on the support substrate 31 (such as many types of polymer materials). Its characteristics are: the shape of the microstructure of the graphic can be a three-dimensional characteristic structure, the thermal printing efficiency and precision are high, the scale of the characteristic structure is wide, and the cost is low.

Referring to accompanying drawing 2～4, adopt the ultrafast laser device of controllable output power on metal roller workpiece according to the arbitrary function of χ, θ _x position (as y=kx, k is a constant, as long as the mathematical analytical formula can express ) to form varying processing depths is the key to micron-scale three-dimensional structures.

Fig. 3 a, b has provided the schematic diagram of the microstructure 24 that laser processing goes out; The laser beam moves according to processing direction 25, can obtain the processing pattern 26 of microstructure depth direction under the control of computer 4;

The size combination of the three-dimensional microstructure that can be processed is: the minimum cross-sectional width of the structure L<50μm, the depth range 0<H<500μm, and the inclination angle range 90°<α<120°. Compared with the conventional micro-nano manufacturing process, the present invention can realize the formation of structures in a large-scale range as small as a micron, and the cross-sectional profile of the structure is a non-straight arbitrary shape.

The diamond-like transition layer 29 with nanoscale thickness in the present invention is very important to change the physical and chemical properties of the microstructure surface of the drum (metal) mold 10 . The diamond-like transition layer 29 will be attached to the surface of the metal mold, endowing the mold with self-lubricating properties, corrosion resistance, wear resistance and moderate surface hardness. Self-lubrication has the effect of release agent on the separation of the rolling die from the thermoplastic or thermosetting processed material during the production process. The diamond-like transition layer 29 is used as the actual surface in production, and its corrosion resistance acts as a protective layer in the cleaning of the metal mold (acid-base solution); the wear resistance and high surface hardness can reduce the deep submicron three-dimensional surface during the rolling process. The wear and deformation of the structure can improve the service life of the rolling die.

The sputtering process of the diamond-like transition layer (accompanying drawing 5), the mold degumming process and the rolling mold manufacturing process (accompanying drawing 6).

Compared with other micro-nano manufacturing processes, the method of the present invention is more suitable for the ability to produce three-dimensional structure products with micron-scale to sub-millimeter scale, and the three-dimensional rolling mold with micron-scale features prepared by the present invention, and adopts the rotary rolling method. There are great advantages in terms of efficiency and cost.

Taking the production of a certain metal (such as stainless steel OCr19Ni9) rolling mold as an example, the specific implementation process is as follows:

(1) Construction of laser processing motion platform. Using commercially available stepping motors and drivers (subdivision drive resolution can reach micron level), guide rail screw, 2-axis motion control card, ultra-fast laser and deflection focusing system (such as Cyber-Laser produced in Japan), etc., As shown in Figure 1, build a micron-level laser processing motion platform;

(2) Micron-scale three-dimensional laser sintering space region forming. Using an ultrafast laser with controllable output power, different output powers are set when the laser beam spot scans to different surface positions to obtain different sintering depths. The sintering depth H can be taken as a function H=f(x, θ _x ) of the desired x, θ _x positions, thereby generating a three-dimensional exposure space area. The laser beam spot can be focused to a minimum of 1 μm, so the minimum line width that can be processed on the mold can reach 1 μm, and the sintering depth is determined by the laser beam power, which can reach 500 μm; in the process of laser sintering, in order to avoid high temperature sintering Nitrogen is used to protect the sintering area from the corrosion of oxygen in the sintering area. In order to avoid the accumulation of residues in the sintering area during the rapid laser sintering process, a vacuum slag discharge conduit 20 (as shown in Figure 2) is used; in order to improve the depth of laser sintering, the laser beam spot Focusing to the minimum, the scanning area can be overlapped (as shown in Figure 3a, b) to achieve a predetermined processing width and depth; in order to achieve continuous laser processing, the scanning method shown in Figure 4 is used;

(3) Depositing a diamond-like transition layer. Use a commercially available coating machine to deposit carbon atoms onto the surface of the rolling mold (which already contains a three-dimensional structure cavity with a micron scale), forming a diamond-like transition layer film 29 with a thickness of nanoscale, as shown in Figure 5;

(4) Using the micron-scale three-dimensional structure rolling mold made by the present invention, the stainless steel mold is stably and continuously heated by the resistance heater inside the roller, and the micron-scale three-dimensional structure on the surface of the mold is thermally printed on the plane by continuous rolling. On thermoplastic or thermosetting materials (such as plexiglass), the productive processing of micron-scale feature three-dimensional structures on such materials is realized, as shown in Figure 6.

Claims (3)

1. the three-dimensional rolling die of a micrometer-class, rolling die is the metal roller structure, be inlaid with resistance type heater between the internal diameter of cylinder and the external diameter, it is characterized in that, be formed with through Laser Processing on the external diameter surface of above-mentioned cylinder, generate the laser sintered area of space on three-dimension curved surface border until sintering on this drum die external diameter surface, laser sintered area of space finally forms the roll-in figure of micron order to the submillimeter level three-dimensional structure, the size combinations of the structural section of this roll-in figure three-dimensional feature is: cross section minimum widith: L＜50 μ m, the degree of depth: 0＜H＜500 μ m, the angle of inclination: 90 °＜α＜120 °, the roll-in figure is covered by one deck diamond like carbon transition film.

2. the method for making of the three-dimensional rolling die of the described micrometer-class of claim 1 is characterized in that comprising the following steps:

At first build the Mold Making platform, the Mold Making platform comprises:

A direction motion platform, this motion platform can realize that the rectilinear direction translation reaches the rotation around rectilinear direction, and this motion platform is controlled by computing machine;

Described motion platform is provided with guide rail and leading screw and drives guide rail and carries out straight-line slide block, be equipped with web joint on the slide block, the web joint two ends have motor to support and bearings respectively, motor has electric rotating machine on supporting, and electric rotating machine and bearings one are used from installs drum die to be processed;

Dispose the laser instrument fixed support on the next door of motion platform, the laser instrument fixed support is provided with laser instrument, this laser instrument is also controlled by computing machine, be equipped with the laser instrument focusing system on the light path of laser instrument, mechanical shutter, vacuum deslagging conduit and gas protection tube road are arranged respectively from the laser beam both sides that the laser instrument focusing system comes out;

The drum die that resistance type heater is housed is mounted on electric rotating machine and the bearings, regulate the focalizer of laser instrument, make that the hot spot that focuses on drum die surface to be processed is the micron order size, after laser output power is stable, begin to process;

The laser beam that laser instrument sends enters the laser instrument focusing system; Under the blanket gas that the laser beam of coming out from the laser instrument focusing system feeds in the gas shield pipeline by mechanical shutter, directly sintering forms microstructure graph on the surface of drum die; This microstructure graph is the three-dimensional structure of micrometer-class size, the residue that the laser beam sintering process forms, take away by vacuum deslagging conduit, by the output power of real time computer control laser instrument and the movement velocity of Mold Making platform, control laser is to the working depth of drum die, to realize the processing of die surface arbitrary characteristics curve shape;

To not needing the processed mould surface, close mechanical shutter, this moment, laser beam was for out-of-focus appearance, can not cause damage to drum die material to be processed, after machined surface to be scheduled to moves to Working position, mechanical shutter is opened, proceed Laser Processing, generate the laser sintered area of space on three-dimension curved surface border until sintering on the drum die external diameter surface, laser sintered area of space finally forms the roll-in figure of micron order to the submillimeter level three-dimensional structure, and the size combinations of the structural section of this roll-in figure three-dimensional feature is: cross section minimum widith: L＜50 μ m, the degree of depth: 0＜H＜500 μ m, angle of inclination: 90 °＜α＜120 °;

At last with coating machine with the roll-in patterned surface of charcoal atomic deposition to micron order to the submillimeter level three-dimensional structure, forming thickness is nano level diamond like carbon transition layer film.

3. method as claimed in claim 2 is characterized in that, described laser instrument is the ultrafast laser of power controlled.

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