Must3

Solderability testing is used to determine if the solderable surface in question will wet with molten solder.

If the BGA is ‘balled’ you are presenting the solder ball to the molten solder of the globule. These two materials are fusible ie they will both melt, the wetting curve produced will be meaningless in that you are not testing the BGA properly. The true solderable surface that should be tested are the pads the solder balls sit on.

There 3 rosin based flux types available, SMNA is a non-activated flux, Actiec 2 is a low activated flux (0.2%) & Actiec 5 is a high activated flux (0.5%).

Generally speaking, Actiec 5 is the best flux to use.

When testing large ‘Odd form’ components such as inductors, connectors, relays etc, the thermal mass of the component under test can be substantial & the heat generated by the solder pellet is not enough to heat up the component. 

There are several ways to overcome this.

1. Try using the solder bath
2. Extending the test time
3. Use some form of pre-heat
4. Typically, the best way is to remove the leg from the component & test this as an individual component.

The below steps outline the correct procedure;

1. Bend away the adjacent legs to the leg being tested such that you are only presenting one leg of the component to the solder during the test
2. Present the leg of the component to the solder at an angle of 20° - 45° to the vertical - Solder to leg alignment is critical
3. Align the sole of the leg to ensure it meets the curved section of the solder pellet – NOT the top of the pellet - see Fig. 1

The MUST3 Solderability Tester is designed to conduct solderability testing in full compliance with a wide range of industry standards, including IEC, IPC, MIL STD, EIA/JEDEC, ISO, JEITA, JNC, and many user-specific methods.

Along with the Solder Bath & Globule set, the MUST3 comes with a comprehensive set of accessories, including solder pellets (SnPb and Lead-free) appropriate for each globule size, 3 types of flux, a set of 13 clips to suit most components, a comprehensive solderability testing manual, and the NPL solderability testing best practice guide.

The MUST3 helps reduce production costs by identifying solderability issues early in the process. This prevents costly rework or replacements later on, saving both time and resources. By ensuring components meet industry standards, you can avoid defects that lead to expensive repairs or product failures.

By ensuring that components have optimal solderability, the MUST3 helps manufacturers achieve reliable solder joints, which are crucial for the proper functioning of electronic products. This testing prevents defects like poor soldering and cold joints, thereby enhancing overall product quality and reliability.

As the Load Cell of the MUST3 is very sensitive, excessive vibration & air currents can affect the Load Cell. The MUST3 should be placed on a solid bench or table located on a solid floor. The air flow around the MUST3 should at a minimum, so excessive airflow from Air Conditioning units etc should be avoided.

It is best practice to test the components at ‘Goods Inward’. It cannot be guaranteed that the components you are supplied with are in a good solderable condition.

Prior to the components going into production, they can be tested again to ensure that after storage, they are still fit for purpose.