优特尔告诉您：锡膏颗粒度对焊接有哪些影响

熟悉锡膏的人都知道，锡膏有一个“颗粒度”的属性，这是辨别锡膏档次的一个重要属性。锡膏颗粒的大小对焊接有极大的影响，如果尺寸大，那么颗粒之间存在的间隙也随之增大，充填间隙的助焊液比例也会增加。这有助于焊接时更好的去除氧化物，但是金属含量不足会对吃锡造成影响。今天我们就来深入地了解下锡膏颗粒度对焊接的影响。

Familiar with the paste knows, the paste has a "size" attribute, which is an important attribute to identify the grade of solder paste. The solder paste particle size has great influence on the welding, if the size is large, so the gap between the particles are also increased, soldering fluid will also increase the proportion of gap filling. This helps when welding better remove oxides, but the metal content of tin deficiency will affect. Today we have to deeply understand under the influence of particle size on welding solder paste.

锡膏的金属粉未是在惰性气体中将熔融的焊料雾化而制成的微细粒状金属。锡膏中金属粉未的颗粒有三种形状:即球形、近球形和不定形。

Metal powder solder paste is not in the inert gas atomization of molten solder made of fine granular metal. Granular metal powder paste has three kinds of shapes: spherical or near spherical and amorphous.

锡膏焊料的颗粒形状、直径大小及其均匀性也影响其印刷性能，一般焊料颗粒直径约为模板开口尺寸的1／5，对细间距0．5mm的焊盘来说，其模板开口尺寸在0．25mm，其焊料粒子的最大直径不超过0．05mm，否则易造成印刷时的堵塞。具体的引脚间距与焊料颗粒的关系如表1所示。通常细小颗粒的焊膏会有更好的焊膏印条清晰度，但却容易产生塌边，同时被氧化程度和机会也高。一般是以引脚间距作为其中一个重要选择因素，同时兼顾性能和价格。

Solder paste solder particle shape, size and uniformity of printing performance and general solder particle diameter about template opening size of 1 / 5, the pads for fine pitch 0.5mm, the template opening size in 0.25 mm, the maximum diameter of the solder particles of not more than 0.05mm, otherwise easily lead to printing the blockage. The relationship between pin spacing and solder particles is shown in table 1. Usually have better small particles of solder paste solder paste printing a definition, but it is easy to produce edge collapse and degree of oxidation and the opportunity is also high. General is to pitch as one of the important factors, both performance and price.

在相同的质量下，球形的表面积是最小的。表面积越小被氧化的可能性便越小，越小的氧化便对焊接越有利.不定形颗粒没有明显的形状和细度，这种锡膏有较大的表面氧化比，故焊接性能较差，近球形则介于两者之间.所以应选择球形或近球形的锡膏。

In the same quality of the spherical surface area is the smallest. The surface area of the smaller the possibility of oxidation will be smaller, the smaller the oxidation of welding more favorable amorphous particles have no obvious shape and fineness of the solder paste is larger than the surface oxidation between the welding performance is nearly spherical somewhere so choose spherical or nearly spherical paste.

锡膏颗粒越大，充填间隙的助焊液越多，还原氧化的能力也越好。颗粒越小，总的表面积越大，颗粒排列越紧密，助焊剂相对会少一些，对焊接时还原氧化物比较不利。

Paste the larger particles, soldering fluid more gap filling, the better the redox ability. The smaller the particle size, the total surface area is larger, the particles are arranged more closely, the relative flux will be less, the welding oxide reduction compared with a negative.

金属颗粒比较小时，颗粒之间排列比较紧密，金属含量增加对焊锡膏的印刷以及形成合金会有帮助，但是金属表面积也会增加，氧化物也随之增加。锡膏颗粒越细对锡膏印刷性有利，因间隙小，细颗粒内的助焊剂含量比大颗粒的要少。锡膏颗粒尺寸的大小是通过网目数决定的，单位内的网目数量越多颗粒越细。

The metal particles is small particles arranged more closely, increase of metal content of solder paste printing and alloy formation will help, but will also increase the surface area of metal oxide, also increases. Paste the finer particles in favor of solder paste printing, because the gap is small, the flux content of fine particles within the large particles is less than. The paste particle size is determined by the number of net mesh size, mesh units within the finer particles.