Could you briefly discuss the effective methods for detecting the alloy composition and particle size of tin powder in solder paste?

Generally speaking,Solder pasteIt is a paste-like mixture formed by mixing tin powder, flux, and other surfactants, thixotropic agents, etc. Its characteristics are determined by the alloy composition of the solder paste. How to know the alloy composition of tin powder in solder paste? The following Shenzhen solder paste manufacturer will share effective methods for testing the alloy composition and particle size of tin powder:

I. Effective methods for testing the composition of tin powder alloys:

On the one hand, the purpose of my test is to ensure that the composition of the alloy and the proportion of impurities must comply with the test standard specifications.

On the other hand, the testing instrument used: Spark direct reading spectrometer.

The last detection method:

1Take a sample from the solder paste approximately250gThen clean the flux in the solder paste thoroughly with a solvent.

2Heat it to form a tin block.

3Place the tin block sample on the spark emission spectrometer for testing.

4Probably at30Seconds later, a form for determining the proportion of alloy impurities to be tested will be automatically printed out on the computer.

By comparing the data obtained from the test with the alloy composition of the actual solder paste, it can be determined whether this solder paste is the one we widely use.

Ii. Effective methods for testing the particle size of tin powder

Usually, we cannot distinguish the particle size and shape of tin powder with the naked eye, so we have to rely on testing instruments: laser particle size analyzers.

The testing method: Take the sample out of the solder paste bottle50GTake advantage of its appearance80Observe the appearance of tin powder under a microscope larger than magnification. And the particle size distribution range of tin powder is automatically calculated through random sampling. At the same time, carefully observe whether the shape of tin powder presents as "true spherical" or "indefinite shape". The entire process needs to be recorded in real time, and the last calculation will produce the result.

We can all choose the appropriate particle size of solder paste based on different products. Currently, the common particle sizes are generally divided into two standards:3#powder25～45umBetween4#powder20-38umBetween.

During the printing process, detecting the particle size and shape of tin powder can help us understand the properties of tin.