Solder Ball Harmonized Code

Using BGA solder balls in solder sphere placement machines

Recent­ly, a cus­tomer using BGA sol­der spheres in a semi-auto­mat­ic BGA sol­der balls place­ment machine asked if it was ok to leave these sol­der spheres for sev­er­al days in the tray, or they should be removed and placed back in the jar after the pro­duc­tion cycle was complete.

Do BGA Solder Balls Oxidize?

The rea­son the cus­tomer asked this ques­tion was because our sol­der spheres come packed in Nitro­gen (N2), which keeps them from oxi­diz­ing. The oxi­da­tion pro­ce­dure is not instan­ta­neous but builds up after a long time, ulti­mate­ly mak­ing the sol­der joints less reli­able. By keep­ing them in N2, the sol­der balls can be kept for a long time (min­i­mum shelf-life of Nitro­gen-stored sol­der spheres is 1 year) in ambi­ent or room tem­per­a­ture with­out the need for spe­cial treat­ment before use. How­ev­er the time that it takes to build up an oxi­da­tion lay­er that is thick enough to affect the sol­der joint reli­a­bil­i­ty is quite long, think in terms of months, not hours, days or weeks. There­fore our answer was that it was not nec­es­sary to take the sol­der balls from the trays after a pro­duc­tion run, and they can leave the sol­der spheres on the trays for sev­er­al days with­out fear of oxi­da­tion affect­ing joint reliability.

BGA Solder Balls in Smaller Jars

Putting the sol­der spheres back into the jars would be point­less any­way as they arrive sealed with a lay­er of N2, and to sim­ply put them back in the jar with the lid on does noth­ing to pre­vent oxi­da­tion. On the oth­er hand, CAPLINQ real­izes that small­er cus­tomers pre­fer small­er pack­age sizes, and recent­ly intro­duced a new pack­ag­ing of 250,000 spheres per jar instead of our pre­vi­ous 1 mil­lion spheres per jar. This allows cus­tomers to keep pack­ages sealed before they need them.

CAPLINQ sup­plies a range of sol­der spheres includ­ing Tin/Lead (Sn63Pb37) Sol­der Spheres or our Lead­free (Pb-free) Sol­der Spheres includ­ing SAC105, SAC125N, SAC305, SAC387, SAC396 or SAC405 and 4N Pure Tin Sn100 Sol­der Spheres.

We also now offer Bi58Sn42 Eutec­tic Lead­free Sol­der Spheres and Bi57Sn42Ag1 Near-Eutec­tic Lead­free Sol­der Spheres. You can also con­tact us if you have fur­ther ques­tions on buy­ing BGA sol­der balls.

About Chris Perabo

Chris is an energetic and enthusiastic engineer and entrepreneur. He is always interested in taking highly technical subjects and distilling these to their essence so that even the layman can understand. He loves to get into the technical details of an issue and then understand how it can be useful for specific customers and applications. Chris is currently the Director of Business Development at CAPLINQ.

One thought on “Using BGA solder balls in solder sphere placement machines

  1. Cop­per spheres are used in BGA appli­ca­tions and attached to the chip with a high-melt­ing alloy. This prop­er­ties of cop­per make these spheres ide­al for replac­ing tra­di­tion­al tin/lead alloys for lead-free applications.

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