CN1316304A

CN1316304A - Process for preparing copper film

Info

Publication number: CN1316304A
Application number: CN 00110288
Authority: CN
Inventors: 卢磊; 斯晓; 陶乃鎔; 隋曼龄; 卢柯
Original assignee: Institute of Metal Research of CAS
Current assignee: Institute of Metal Research of CAS
Priority date: 2000-04-05
Filing date: 2000-04-05
Publication date: 2001-10-10
Anticipated expiration: 2020-04-05
Also published as: CN1116130C

Abstract

A technology for preparing copper film uses the nm metal copper as raw material with crystal grain size less than 100 nm, purity of 99.995 wt.% and density of 8.91+/-0.03g/cu.cm, and features that said copper is cold rolled at ordinary temp with deforming rate of 0.00001-0.1/S. Its advantages include high surface quality and very small thickness.

Description

A kind of preparation method of copper film

The present invention relates to the technology of preparing of metallic material film, a kind of preparation method of copper film is provided especially.

So-called " film " be meant to three-dimensional space wherein one dimension be very little, this one dimension refers to the thickness of film, it has been generally acknowledged that the film of the following thickness of 1 μ m is a film, the above person of 1 μ m is a thick film, but does not have obvious limit here.The method for preparing metallic membrane has many kinds, industry in 18th century, and people just can prepare solid film by electroless plating and glow discharge deposition.In recent years, developed vacuum evaporation deposition, thermospray, sputtering sedimentation or the like technology of preparing again in succession, in the mechanical workout, rolling method also commonly used reduces the size of product thickness direction, and this method is widely used in the plastic working field.Rolling technology is relevant to Deformation velocity, deformation extent, temperature parameter or the like with many factors, rollingly when rolling, whether produce softening (replying and recrystallize) immediately by metal and be divided into hot rolling and cold rolling, generally metal at recrystallization temperature (0.4Tm, Tm is a fusing point) above rollingly be called hot rolling, and the cold rolling material that is meant directly at room temperature carries out without heating.General with the blank of specializing in cold rolling usefulness that passes through hot-roll forming or hot-finished material as raw material, on cold-rolling mill, be rolled behind the descaling.When cold rolling in the metal because of the motion and the long-pending work-hardening effect that produces in various degree of plug of dislocation, thereby limited the distortion of materials ability.This work-hardening effect just can be carried out further machining deformation after must eliminating by appropriate heat treatment.Therefore, hot and cold processing treatment has repeatedly become the traditional technology of most metal material processing distortion.Though it is good that cold rolling material has surface quality, characteristics such as physical strength height, when cold rolling between passage deflection little, annealing process is loaded down with trivial details, and economic cost is big etc., and shortcoming also often makes it to be restricted.In addition, being pricked the material final thickness, also thicker (the rolled minimum thickness of normal four-roller cold-rolling mill is 0.25mm.

The object of the present invention is to provide a kind of preparation method of copper film, its copper film surface quality of preparing is good, can reach very thin thickness, and technology is simple, uses common rolling equipment to realize.

The invention provides a kind of preparation method of copper film, it is characterized in that: is starting material with grain-size less than the nano metal Cu of 100nm, and purity is higher than 99.995wt%, and density is 8.91 ± 0.03g/cm ³, at cold rolling at room temperature, rate of deformation: 1 * 10 ^-5～1 * 10 ¹/ s.

The present invention is by carrying out rolling deformation under the room temperature to nano metal Cu material, need not any annealing and other treating processes that eliminates stress in the operation of rolling, obtain the Cu mould material of aximal deformation value high-elongation, and the grain-size of Cu film remains unchanged in the operation of rolling, does not also have tangible work-hardening effect in the material.The excellent properties of nano material is added journey with material combine, utilize the nano metal material particular structure, need not stress relieving by annealing with the rolling method of room temperature first, and obtain the Cu film about 20 μ m.The rolling Cu of the obtaining film of the room temperature of nano metal Cu means that metallic substance nanometer after-processing technology process can simplify greatly, this will have significant values to manufacturing of retrofit, electron device and the micromachine of material etc., simultaneously, also be a challenge to material tradition deformation mechanism.Below by embodiment in detail the present invention is described in detail.

The photomacrograph of the nanocrystalline Cu sample of rolling attitude of different distortion amount under accompanying drawing 1 room temperature condition.

The microstrain (empty circle) of accompanying drawing 2 electrolytic deposition nanometer Cu samples and the microstrain (real circle) of average grain size (short side piece) and the thick Cu sample of annealed state are with the variation tendency of cold rolling reduction.

Accompanying drawing 3 high-resolution electron microscopies are observed the microtexture of rolling back cu film.

The micro-hardness of accompanying drawing 4 electrolytic deposition nanometer Cu samples, the thick Cu sample of annealed state and common thick Cu sample is with the variation tendency of cold rolling reduction.

Embodiment 1:

The nanometer Cu sample that one section grain-size of 16mm * 4mm * 1mm is 30nm is cold rolling at ambient temperature, find that sample constantly increases along rolling direction length, the thickness direction size constantly reduces, and sample width almost constant (＜5%).Through constantly rolling, sample is more and more longer, and last nanocrystalline Cu sample becomes the film band that a smooth surface does not have any crackle all around, and this moment, total deformation was about 5100%, as shown in Figure 1.Cu membrane sample thickness is about 20 μ m (this is the thickness limit of this milling train) during rolling end, further rollingly still can carry out.

Embodiment 2:

Quantitatively the x-ray measurement result shows, nanocrystalline Cu The grain size is all the time about 30nm in cold-rolled process, and the microstrain in the material raise greatly in the starting stage (ε＜1000%), this principal reaction the variation of dislocation desity in the sample.And when ε 〉=1000%, its microstrain reaches a saturation value and is about 0.16% (see figure 2).And in the thick Cu sample of annealed state, the version of microstrain but with the microstrain Changing Pattern completely different (as shown in Figure 2) of nanocrystalline Cu.

Embodiment 3:

High-resolution electron microscope is observed the microtexture of cold rolling back nanometer Cu sample and is found that in the operation of rolling, the grain size in the nanocrystalline Cu sample does not almost change, and grain shape still is an equiax crystal.But in the nanocrystalline Cu sample of rolling attitude, dislocation desity (mainly concentrating on the crystal boundary place) obviously increases, the misorientation of crystal grain and intergranule has also obviously increased, statistics shows, the misorientation of intergranule is approximately 6～18 ° in the nanocrystalline Cu sample in abundant rolling back, and this will be apparently higher than the grain orientation in the nanocrystalline Cu sample of electrolytic deposition attitude poor (1～10 °).As shown in Figure 3.

Embodiment 4:

The micro-hardness experimental result shows that in cold-rolled process the hardness of electrolytic deposition nanometer Cu sample is increased to 1.20GPa (ε=800%) in the starting stage from 1.05GPa (deposition attitude), as shown in Figure 4.Continue cold rollingly, then do not have work-hardening effect in the nanometer Cu sample ¹ε＞800%).

Embodiment 5:

With grain-size is that the nanometer Cu sample of 70 nm is cold rolling at ambient temperature, finds that equally this sample can be about 20 μ mCu films by at room temperature cold rolling one-tenth thickness.

Comparative example 1:

The pure Cu sample of cold rolling common coarse-grain is found under same condition, and when deflection was approximately 800%, existing tangible crackle produced.

Comparative example 2:

The nanocrystalline Cu sample of 30nm was annealed 48 hours under 500 ℃ of vacuum conditions, make its crystal grain fully grow up (grain-size is greater than 100 μ m).Cold rolled annealed attitude Cu sample under identical condition is found equally when deflection is about 700%, and existing obvious crackle produces around the sample.Can get rid of the influence of purity by above experiment contrast to the sample temperature-room type plasticity.

Comparative example 3:

Under same cold rolling condition, then exist tangible work-hardening effect in the common thick Cu sample of cold rolling attitude: as can be seen from Figure 4, the hardness of common thick Cu sample is increased to 1.57GPa (ε=800%, crackle produces) from the 0.61GPa of former primary state; The hardness of annealed state Cu sample is increased to 1.45GPa (ε=650%, crackle produces) from 0.51 GPa (annealed state).The different trend of changes in hardness have illustrated deformation mechanisms different between the two in this coarse-grain Cu sample and the nanocrystalline Cu sample.

Claims

1, a kind of preparation method of copper film is characterized in that: is starting material with grain-size less than the nano metal Cu of 100nm, and purity is higher than 99.995wt%, and density is 8.91 ± 0.03g/cm ³, at cold rolling at room temperature, rate of deformation: 1 * 10 ^-5～1 * 10 ¹/ s.