Overview of leaded solder paste and where to buy quality leaded solder paste


Leaded solder paste is a form of solder paste mainly used in the process of attaching components and SMDs to the surface of PBC printed circuit boards. Let’s learn more about this material in the article below!

What is leaded solder paste? 

Leaded solder paste, solder paste is a form of solder paste. But instead of making it as a rod, in a roll, it is made in a wet form.

Leaded solder paste

This is a mixture that is mixed from solder particles and fluxes in certain proportions. The solder particles can be pure tin or a mixture of tin and lead. Besides, it is also possible to add some other metals such as Silver, Copper,… Normally, this ingredient will account for about 80-90% of the product volume.

Since the product is made in the form of a cream, it does not need to be melted as when using tin solder. This will save businesses a lot of time. At the same time, the solder paste also helps the components stick to the printed board surface more easily.

Leaded solder paste is divided into how many types?

Current solder paste is classified based on solder particle size and by its composition.

Classification according to solder paste particle size

Based on the solder particle size, solder paste will be classified as follows:


Type Particle size (mm)
Loại 1 75 – 150
Loại 2 45 – 75
Loại 3 25 – 45
Loại 4 20 – 38
Loại 5 10 – 25
Loại 6 5 – 15
Loại 7 2 – 11
Loại 8 2 – 8


Because the solder particles cannot be determined to a specific value, the size will fall between a range of values.

Classification by composition

Based on the composition, solder paste will be divided into 2 types. There are leaded solder paste and lead-free solder paste ones.

Solder paste contains lead: As the name suggests, in its composition contains lead element combined with tin to form a mixture. Typically, the tin to lead ratio in this solder paste can be 63% Tin and 37% Lead or 60% Tin and 40% Lead.

Lead-free solder paste: This is a solder paste from pure tin, mixed with some other elements such as Silver, Copper, etc. Usually, the ratio of lead-free solder paste is commonly used. are 96.5% Tin, 3% Silver and 0.5% Bronze.

Leaded solder paste

Instructions for proper storage and use of leaded solder paste

To ensure that the leaded solder paste achieves the highest performance when used, you need to understand the instructions for proper care and use of the product as follows:

Methods of preservation 

Solder paste must be stored at a low temperature, from 2 – 10 degrees Celsius is the appropriate temperature to slow down the oxidation of the product.

Solder paste needs to be stored in a sealed container, if after opening the lid but not using it all, take the required amount of solder paste and tighten the lid, store in a cold place.


After removing the solder paste from the storage place, leave the solder paste at room temperature for about 2 hours for the leaded solder paste to return to its normal state.

Use special materials to stir the solder paste evenly. Do not stir for a long time, stir for about 2-3 minutes to start using.

To apply solder paste on the printed circuit board and in the correct position to solder, you should use the Pencil PCB tool

Leaded solder paste

Thetech – The company specializes in providing quality imported leaded solder paste

If customers want to buy leaded solder paste but don’t know where to buy it, please come to Thetech! This is a company specializing in providing genuine imported leaded solder paste at the best prices on the market today. 

Thetech solder paste products are fully stamped, inspection cards, certificates of origin. So customers can rest assured when shopping here.

Above is an overview of leaded solder paste and a reputable place to buy leaded solder paste. Hopefully through this article, you have a better understanding of this material. If you have any questions, don’t hesitate to contact Thetech to get answers!

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