CN107999908B

CN107999908B - Manufacturing method of micro-pit array

Info

Publication number: CN107999908B
Application number: CN201810016919.8A
Authority: CN
Inventors: 秦歌; 刘凯瑞; 曲海军; 闫亮; 张云燕; 周奎
Original assignee: Henan University of Technology
Current assignee: Henan University of Technology
Priority date: 2018-01-09
Filing date: 2018-01-09
Publication date: 2022-04-01
Anticipated expiration: 2038-01-09
Also published as: CN107999908A

Abstract

The invention discloses a manufacturing method of a micro-pit array, which comprises the following steps: (1) a suspension of magnetic colloidal particles was prepared. (2) Preparing a magnetic colloid particle film on the surface of the workpiece. (3) The workpiece is taken as an anode, magnetic poles parallel to the electrodes are added on the outer sides of a cathode and an anode of the electrolytic bath, magnetic colloid particles are firmly pressed on the surface of the workpiece under the action of a magnetic field generated by the added magnetic poles, the workpiece with the surface coated with the magnetic colloid particles is taken as the anode, the magnetic colloid particles on the surface of the workpiece are taken as a mask, and the workpiece is subjected to electrolytic corrosion processing in gaps among the magnetic colloid particles. (4) Removing the magnetic colloid particles to obtain the micro-pit structure. The invention utilizes the effect of magnetic field force on magnetic colloid particles, effectively solves the problem of insufficient adhesion between the colloid particles serving as the mask and the substrate in the particle mask electrolytic process, has simple mask fixing mode and simple operation, and can ensure that the process of mask electrolytic machining of the micro-pit array is smoothly carried out.

Description

Manufacturing method of micro-pit array

Technical Field

The invention relates to a manufacturing method of a micro-pit array, belonging to the field of micro-nano processing.

Background

In recent years, the surface micro-pit structure has become a hot point of research due to good performances such as friction resistance, wettability, superhydrophobicity, biocompatibility and the like, and is widely applied to the surface preparation of high-speed and ultrahigh-speed friction pieces, oil-resistant and hydrophobic pieces, biological devices and micro devices.

The common micro-pit array processing method at present comprises the following steps: micromachining, self-excited vibration machining, electric discharge machining, laser beam machining, mask etching, mask electrolytic machining, and the like. The photoetching technology is a common process in micro-nano manufacturing, but the processing cost is high, and the photoetching technology is not suitable for processing and preparing large-area structures, three-dimensional complex microstructures and particularly curved surface structures. Although the development of the gray-scale mask technology and the digital gray-scale lithography technology enables the lithography method to be primarily applied to the preparation of the surface of the three-dimensional continuous relief microstructure, the lithography precision is still affected by the minimum lithography line width, the complexity of the prepared three-dimensional surface shape is limited, and the surface shape controllability is low.

In recent years, colloidal particles are used as a template to manufacture various micro-nano structure arrays in combination with an electrochemical process, and the method is a current research hotspot due to the advantages of simplicity, economy and the like. In actual processing, large-area periodic array structures with different sizes can be prepared only by changing the particle size of colloid particles. However, the colloidal particles may fall off from the substrate during the electrochemical machining process due to insufficient adhesion between the colloidal particles and the substrate in the manufacturing process, so that the prepared microstructure has more vacancies and shallow pit defects and even fails the process. In the existing research, the magnetic field assisted electrochemical process introduces an external magnetic field between electrodes to change the motion track and speed of metal ions, thereby changing certain characteristics of electrochemical processing.

Disclosure of Invention

The invention aims to solve the problem of insufficient adhesive force between colloid particles and a substrate in the existing process for preparing the micro-pits by using the nano colloid particle mask, and provides a micro-pit manufacturing method by utilizing the property that the magnetic colloid particles used as the mask are pressed on the surface of a workpiece under the action of a magnetic field force in a magnetic field, so that the problem of insufficient adhesive force of the colloid particles on the substrate is effectively solved, and the manufacturing of a micro-pit structure array can be effectively realized.

The technical scheme of the invention is as follows:

a manufacturing method of a micro-pit array comprises the following steps.

(1) A suspension of magnetic colloidal particles was prepared. Taking a proper amount of magnetic colloidal particles, putting the magnetic colloidal particles into water, adding a surfactant, and oscillating the mixture in an ultrasonic oscillator for a certain time to obtain a magnetic colloidal particle suspension.

(2) A magnetic colloidal particle film was prepared. And (3) polishing, deoiling, derusting and hydrophilic treatment are carried out on the surface of the workpiece to be processed, and the workpiece is dried for later use. The surface of a workpiece is coated with magnetic colloidal particle suspension liquid in a dripping mode, the magnetic colloidal particle suspension liquid is placed in a drying container in an ultrasonic oscillator, the magnetic colloidal particle suspension liquid is uniformly dispersed on the surface of the workpiece under the action of ultrasonic vibration, and a uniformly distributed single-layer film of magnetic colloidal particles is obtained on the surface of the workpiece after drying.

(3) And (4) electrolytically corroding the micro pits. The workpiece is taken as an anode, magnetic poles parallel to the electrodes are added on the outer sides of a cathode and an anode of the electrolytic bath, the magnetic colloid particles are firmly pressed on the surface of the workpiece under the action of a magnetic field generated by the added magnetic poles, and the workpiece is electrolytically machined in gaps among the magnetic colloid particles by taking the magnetic colloid particles on the surface of the workpiece as a mask.

(4) Removing the magnetic colloid particles to obtain the micro-pit structure. And stopping electrolysis after the processing requirement is met, taking out the workpiece, putting the workpiece into an organic solvent, performing ultrasonic oscillation cleaning, and removing magnetic colloid particles to obtain the micro-pit array.

During the electrolysis process, the electrolytic product can have certain impact effect on the colloid particle mask. Whether the adhesive property between the colloidal particle mask and the substrate is good or not and whether the mask can be kept on the substrate until the end of the electrolytic process are the keys to successfully process the micro-pit array. In the invention, magnetic field force provided by the magnetic poles arranged outside the anode and the cathode of the electrolytic cell can firmly press the magnetic colloid particles on the surface of the workpiece, so that the magnetic colloid particles can still keep the original position even under the action of impact force of an electrolytic product, and the mask electrolytic process can be smoothly carried out.

Compared with the prior art, the invention has the following advantages: the difference with the existing magnetic field assisted electrochemical process is that the magnetic field applied outside the cathode and anode in the electrolytic process mainly has the function of providing pressure for the magnetic colloid particles on the processing surface to firmly press the magnetic colloid particles on the surface of the processed workpiece to realize the masking effect of the colloid particles in the electrolytic process, the masking fixing mode is simple, the reliability is high, the operation is simple, the problem of early separation of the masking particles caused by insufficient fixing force in the preparation of the micro-pit array is solved, and the smooth proceeding of the micro-pit array electrolytic processing process is ensured.

Drawings

Fig. 1 is a schematic diagram of a monolayer magnetic colloidal particle film prepared on the surface of a workpiece.

FIG. 2 is an apparatus schematic of a process for mask electrochemical machining of an array of micro-pits under the influence of a magnetic field.

FIG. 3 is a schematic illustration of an array of micro-pit structures resulting from mask electrochemical processing.

Number designation in the figures: 1. magnetic colloid particles, 2, a workpiece, 3, a cathode of an electrolytic cell, 4, a magnetic pole and 5, a micro pit.

Detailed Description

The present invention will now be described in detail with reference to the accompanying drawings.

A processing method of a dimple manufacturing technique of this example includes the following steps.

(1) A suspension of magnetic colloidal particles was prepared. Taking a proper amount of magnetic colloidal particles 1, putting the magnetic colloidal particles into water, adding a surfactant, and oscillating the mixture in an ultrasonic oscillator for a certain time to obtain a suspension of the magnetic colloidal particles 1.

Preferably, the surfactant may be polyethylene glycol.

Preferably, the material of the magnetic colloidal particles is a ferromagnetic material such as iron, cobalt, nickel, and alloys thereof.

The magnetic colloid particles are preferably uniform in diameter and size, and the magnetic colloid particles are preferably 300nm to 100 μm in diameter according to the size of the required micro-pit array.

(2) A magnetic colloidal particle film was prepared. And (3) polishing, deoiling, derusting and hydrophilic treatment are carried out on the surface of the workpiece 2, and the workpiece is dried for later use. The suspension of the magnetic colloidal particles 1 is dripped on the surface of the workpiece 2, the suspension is placed in a drying container in an ultrasonic oscillator, the suspension of the magnetic colloidal particles 1 is uniformly dispersed on the surface of the workpiece 2 under the action of ultrasonic vibration, and a single-layer film of the magnetic colloidal particles 1 which are uniformly distributed is obtained on the surface of the workpiece 2 after drying.

Preferably, the workpiece should be made of a material with good conductivity and good electrolytic corrosion, and the material of the workpiece selected in the example is nickel, copper and aluminum.

Preferably, the ultrasonic vibration time in the ultrasonic oscillator is 15-30 min.

(3) And (4) electrolytically corroding the micro pits. The workpiece 2 is taken as an anode, parallel magnetic poles 4 are added on both sides of a cathode 3 and the anode of the electrolytic bath, magnetic colloid particles are firmly pressed on the surface of the workpiece 2 under the action of a magnetic field generated by the added magnetic poles 4, and the workpiece 1 is electrolytically machined in gaps among the magnetic colloid particles 1 by taking the magnetic colloid particles 1 on the surface of the workpiece 2 as masks.

Preferably, the electrolyte can be selected from sodium chloride and sodium nitrate solution, and in the embodiment, the sodium chloride solution with the mass fraction of 25% is selected.

Preferably, the applied magnetic poles provide a magnetic force that ensures that the magnetic colloidal particles can be immobilized on the substrate, in this example a magnetic field with a field strength of 10T is chosen.

(4) Removing the magnetic colloid particles to obtain the micro-pit structure. And stopping electrolysis after the processing requirement is met, taking out the workpiece 2, putting the workpiece into an organic solvent, performing ultrasonic oscillation cleaning, and removing the magnetic colloid particles 1 to obtain the micro-pit 5 array.

Preferably, the organic solvent is ethanol or acetone.

Claims

1. A manufacturing method of a micro-pit array is characterized by comprising the following steps:

(1) preparation of magnetic colloidal particle suspension: putting a proper amount of magnetic colloidal particles into water, adding a surfactant, and oscillating for a certain time in an ultrasonic oscillator to obtain a magnetic colloidal particle suspension;

(2) preparing a magnetic colloid particle film: polishing, deoiling, derusting and hydrophilic treatment are carried out on the surface of a workpiece to be processed, and drying is carried out for later use; dripping magnetic colloidal particle suspension liquid on the surface of a workpiece, putting the magnetic colloidal particle suspension liquid into a drying container in an ultrasonic oscillator, uniformly dispersing the magnetic colloidal particle suspension liquid on the surface of the workpiece under the action of ultrasonic vibration, and drying to obtain a uniformly distributed single-layer film of magnetic colloidal particles on the surface of the workpiece;

(3) electrolytic corrosion micro-pits: using a workpiece as an anode, adding magnetic poles parallel to the electrodes at the outer sides of a cathode and the anode of an electrolytic bath, firmly pressing magnetic colloid particles on the surface of the workpiece under the action of a magnetic field generated by the added magnetic poles, and performing electrolytic machining on the workpiece in gaps among the magnetic colloid particles by using the magnetic colloid particles on the surface of the workpiece as a mask;

(4) removing the magnetic colloid particles to obtain a micro-pit structure array: and stopping electrolysis after the processing requirement is met, taking out the workpiece, putting the workpiece into an organic solvent, performing ultrasonic oscillation cleaning, and removing magnetic colloid particles to obtain the micro-pit array.

2. The method of claim 1, wherein the magnetic colloidal particles are made of a ferromagnetic material.

3. The method of claim 1, wherein the magnetic colloid particles have a uniform diameter, and the diameter of the magnetic colloid particles is selected according to the size of the desired micro-pit array.

4. The method of claim 1, wherein the workpiece is made of a material that conducts electricity well and is electrolytically corrodible.

5. The method of claim 1, wherein the magnetic field force provided by the magnetic poles is sufficient to fix the magnetic colloid particles on the substrate.

6. The method of claim 2, wherein the ferromagnetic material is iron, cobalt, nickel or their alloys.

7. The method of claim 4, wherein the material with good conductivity and good electrolytic corrosion is nickel, copper or aluminum.

8. The method of claim 5, wherein the magnetic field strength is 10T.