In general, if BGA packaging can be avoided in design, it should be avoided as much as possible, because BGA packaging is difficult to solder and the soldering inside the packaging cannot be checked.

Circuit board short circuit: When the circuit board is soldered and aging, some circuit boards will be found to be short-circuited. In addition to the problems of circuit board design and electronic components, the following aspects can be used to find out that the tinning time of the circuit board is too short, resulting in poor soldering. The flux itself is not very active, which weakens the wettability and expansibility of the solder. The direction of tin entry into the circuit board is opposite to the direction of the tin wave, and too much oxide on the liquid surface of the solder affects welding.

After soldering, the tin point of the pcb is gray and dull: After soldering, the tin point is found to be gray and dull. There are two aspects to say: one is that the degree of solder is too low. Circuit board welding. When the soldering reaches more than 50% tin, the soldering point will be shiny. On the other hand, the residue of the flux stays on the surface of the tin point without cleaning, and its acid corrodes the soldering point, which will also cause the tin point to be gray and dull.

The surface of the tin spot is rough after soldering: The roughness of the surface of the tin spot of the circuit board should first be discussed from the quality of the solder. The solder itself contains various small amounts of metal elements. When the content of these metal elements exceeds its limit, it will affect the surface of the tin spot. When soldering, the surface of the tin liquid is required to be free of impurities. When the surface of the tin liquid is oxidized too much, it must be cleaned in time, otherwise it will affect the surface of the tin spot.

The color of the solder spot is yellow: The color of the solder spot is yellow, which is a common problem. Many people don’t know why. When the solder appears in color, it is generally related to the temperature. When the temperature of the solder is too high, the surface of the tin liquid turns yellow. At this time, the temperature of the tin furnace should be adjusted to a suitable operating temperature.