化学-电化学协同反应制备电子级超细铜粉的研究

Study on preparation of electronic grade ultrafine copper powder by chemical-electrochemical synergistic reaction

摘要:

国内电解法生产铜粉粒径分布一般在 30 μm以上,且所得铜粉大部分集中在附加值低的中低端领域,无法满足电子信息领域的更高要求。本文采用化学-电化学协同反应制备电子级超细铜粉,探讨了化学反应时间、电流密度和阴极成分等对铜粉的粒度、形貌以及结构等影响。结果表明：随着化学反应时间延长,铜粉粒度逐渐增大,树枝状逐渐密实；随着电流密度增加,粒度逐渐减小,呈分散较好的树枝状。确定较佳工艺条件为：化学反应时间为1 min,电流密度为300 A.m_^-2,铝合金阴极板。在此工艺条件下可得到平均粒度为6.44 μm,松装密度0.828 g.cm_^-3,分散性较好的树枝状超细铜粉。也进一步探明了化学-电化学的协同反应机制是置换反应预先生成晶核,电化学沉积在晶核上原位生长形成树枝状晶体。

Abstract:

The particle size distribution of copper powder produced by the domestic electrolysis method is generally above 30 μm, and most of the copper powder obtained is concentrated in the low-end and low-end fields with low added value, which cannot meet the higher requirements of the electronic information field. This paper uses chemical-electrochemical synergistic reaction to prepare electronic grade ultrafine copper powder, and discusses the influence of chemical reaction time, current density and cathode composition on the particle size, morphology and structure of copper powder. The results showed that with the extension of the chemical reaction time, the particle size of the copper powder gradually increased, and the dendritic shape gradually became dense; with the increase of the current density, the particle size gradually decreased, showing a well-dispersed dendritic shape. The optimal process conditions are determined as follows: the chemical reaction time is 1 min, the current density is 300 A.m_^-2, and the aluminum alloy cathode plate. Under this process, a dendritic ultrafine copper powder with an average particle size of 6.44 μm, a bulk density of 0.828 g.cm_^-3 and good dispersibility can be obtained. It is further proved that the chemical-electrochemical coordinated reaction mechanism is that the substitution reaction generates crystal nuclei in advance, and electrochemical deposition grows in situ on the crystal nucleus to form dendritic crystals.