How to solve the problem of BGA empty soldering in SMT solder paste reflow soldering?

insmtSolder pasteIn processingBGAEmptiness is a problem that often occurs. SoBGAHow is the void formed and how can it be solvedBGAWhere is the void? Next, Shenzhen JJY Solder Paste Manufacturer will talk about itSMTSolder paste reflow soldering emergedBGACauses and solutions of empty welding:

I. Causes of Formation

1The crystal structure of the solder joint alloy is unreasonable.

2,PCBThe design error of the board;

3During printing, the amount of flux paste deposited is either too little or too much;

4The reflow soldering process used is unreasonable.

5Voids mixed in the welding balls during the manufacturing process;

Ii. Solutions

1Furnace temperature curve setting;

2During the heating section, if the temperature change rate is too fast, the gas pairs that escape rapidlyBGAHave an impact;

3The duration of the heating stage is too short: After the temperature rise is completed, the gases that should have volatilized have not completely escaped. These gases continue to escape during the reflow stage, affecting the function of the soldering flux system during the reflow stage.

2The ability of the flux paste to wet the solder pad is insufficient.

The wetting effect of solder paste on the pad is manifested in its cleaning effect on the pad. Due to the insufficient wetting ability of the solder paste, the oxide layer on the solder pad cannot be removed or the removal effect is not ideal, resulting in false soldering.

3The surface tension of the flux paste system in the reflux stage is too high.

The effective combination of rosin and surfactants can fully exert the wetting performance.

4The content of non-volatile substances in the flux paste system is relatively high

It is caused by a relatively high content of non-volatile substancesBGADuring the melting and collapse process of the welding ballBGAThe sinking is blocked, causing non-volatile substances to erode the solder joints or the solder joints to wrap around non-volatile substances.

5Selection of carrier rosin

Compared with the common solder paste system that uses rosin with a higher softening point, yesBGAFor solder paste, since it does not need to provide a so-called anti-collapse ability for the solder paste system, it is of great significance to choose rosin with a low softening point.

insmtIn surface mount technology (SMT) processingBGAThe hazard of voids is that they cause a dense effect of current and simultaneously reduce the mechanical strength of the solder joints. Therefore, reduceBGAVoids can enhance the safety of circuits.

JJY owns16With years of experience in research and development and production, we have a strong technical force and stable product quality. Flagship products:QFNHigh solder climbing rate solder paste, zero halogen solder pasteVOIDLow-porosity solder paste, laser solder paste, water-washed solder paste, and high-reliability ones used in military, aerospace, power, photovoltaic and other industriesSn62Pb36Ag2Solder pasteSn62.8Pb36.8Ag0.4Solder paste6337Solder paste, transparent and colorlessLEDHigh-brightness anti-monument solder pastemini-LED/micro-LEDDie bonding solder paste, high-reliability lead-free low-temperature solder paste, low-temperature solder paste for heat sinks, lead-free medium-temperature solder paste, lead-free high-temperature0307/105/305Solder paste, etc. Proprietary technology, strict quality control, continuous stability, making customers worry-free, efficient, cost-effective and competitive!