As mentioned for AOI, visual appearance for lead-free soldered
joints will likely show a mixture of dull and shiny joints.
This pattern could, of course, be sequentially soldered
using a single nozzle, with the time needed to solder the entire pattern estimated at about 40 sec.
Analysis of chemical composition has shown that the interaction of pure aluminium with the solder containing Ag resulted in formation of transition zone rich in Ag from the solder and aluminium from the soldered
joints were fabricated in a type PZ 810 electric resistance vacuum furnace in [10.sup.-2] Pa vacuum.
With practice, you'll know by feel when you've successfully soldered
for 180s, a thin band of [Cu.sub.3]Sn were observed at the [Cu.sub.6][Sn.sub.5]/Cu interface (Figure 11(b)).
* First, select a tip that is the proper size and geometry for the connection to be soldered
. (Match the width of the tip to the diameter of the pad.) While this may seem like common sense, it is frequently the most overlooked practice.
The target was soldered
by application of Cr/Ni/Ag system of layers and really tested in practice.
The as-received BGAs failed under the lowest force range; convection and laser reballed BGAs were in the middle of the force range, and originally attached balls soldered
with laser in an oxygen-free chemical bath were at the high end of the range.
Replace the elbow with a tee with a threaded fitting soldered
on one end.
The solder side of a double-sided mixed-tech board may also be soldered
by wave solder if the design permits.
If the solder does not cover the pad on the topside of the board and has not traveled to the top of the plated through-hole, then the joint is incompletely soldered