文章信息/Info

Title:

Effect of Silver Powder on Properties of Varistor Paste

文章編號:

1674-3962(2020)06-0496-05

作者:

董寧利; 哈敏; 王丹

（寧夏中色新材料有限公司 寧夏特種材料重點實驗室，寧夏 石嘴山 753000）

Author(s):

DONG Ningli;  HA Min;  WANG Dan

（Ningxia Special Material Key Laboratory, CNMC Ningxia New Material Co., Ltd., Shizuishan 753000,China）

關鍵詞:

壓敏電阻漿料; 銀粉; 觸變性能; 結晶度; 晶粒尺寸

Keywords:

varistor paste;  silver powder;  thixotropy; crystallinity;  grain size

分類號:

TG146.3+2;TB383.3

DOI:

10.7502/j.issn.1674-3962.201908020

文獻標志碼:

A

摘要:

采用不同還原條件制備了兩種微晶銀粉，測試了銀粉的燒損、顆粒尺寸、比表面積、松裝密度和振實密度，結果表明兩種銀粉的物理性能相近，用其分別制備了壓敏電阻漿料,并測試分析了漿料觸變指數、漿料層印刷質量及燒結后形貌、電阻、附著力以及銀粉的晶粒尺寸。結果表明：銀粉的振實密度對漿料粘度影響較大，振實密度高則漿料粘度低，反之則高；銀粉的粒度分布影響漿料觸變指數，粉末顆粒小且不均勻時，則漿料觸變指數高，反之則低；銀粉的結晶度和晶粒尺寸對漿料的燒結性能有較大的影響，在相近的粒度分布范圍內，高結晶度、大晶粒尺寸的銀粉制備的漿料燒結后形成的晶界比較好，漿料層更致密，電阻更低，附著力好。

Abstract:

Two kinds of microcrystalline silver powders were prepared under different reduction conditions, and the burning loss, particle size, specific surface area, bulk density and tap density of silver powders were tested. The results showed that the physical properties of the two kinds of silver powders are similar. The two kinds of sliver powder were applied to concoct varistor paste. The thixotropy index, printing quality, morphology, resistance, adhesion of paste layers, and grain size of silver powders were tested and analyzed. The experimental results showed that the tap density of silver powders has a great influence on the slurry viscosity, high tap density results in low slurry viscosity and vice versa. The particle size distribution of silver powder has a great influence on the slurry thixotropy, if the particle size is small and nonuniform, the thixotropy index is high and vice versa. The crystallinity and grain size of silver powder have great influence on the sintering performance of the slurry. In the similar size distribution range, the grain boundary formed by powders with high crystallinity and larger grain size is better, the sintering is more compact, the paste layer’s resistance is lower, the adhesion is better. Powder with high crystallinity and larger grain size is more suitable for preparing varistor paste.