Learn the production technology of lead-free solder

Lead-free solder has been widely used in the soldering process of electronic components. So are you curious about how these solder tins are produced? Follow along with the article below to learn about the production technology for this solder!

What is lead-free solder?

Lead-free solder is a type of solder that does not contain lead, which is toxic to human health. Accordingly, lead metal will be replaced by many different metals, such as copper, silver, etc., based on a certain ratio.

Lead-free solder can be produced in bar, wet, or wire form. No matter what form it is produced in, it will retain its inherent characteristics. Depending on your needs, you will choose the appropriate lead-free solder form. However, in terms of convenience, the wet form is the most convenient. Because you don’t need to melt it before use, you save a lot of time and effort. Some of the preeminent properties of lead-free solder are:

• It does not produce toxic smoke.
• Good adhesion on component surfaces
• High resistance to oxidation, limiting rust on the surface
• Good stability; improve welding efficiency.

View more: Solder Paste

View more: Solder Bar

Overview of lead-free solder in production technology

In the following section, we will introduce you to the benefits of lead-free solder production technology. At the same time, the production process of this solder will be mentioned to you.

What are the benefits of lead-free solder production technology?

In early 2003, the EU issued the RoHS Code of Standards. This standard prohibits six types of substances that are especially dangerous to the environment and human health in the production process, of which the lead limit is ≤ 0.1%. So only lead-free solder is allowed in these countries.

Besides, as people become more aware of the negative effects of lead on the environment and human health, lead-free solder tins are becoming more popular. Therefore, lead-free solder production technology was born to protect the interests and health of consumers and overcome environmental pollution.

Lead-free solder tin production process

The process of producing lead-free solder will take place sequentially in the following three steps:

Selection of ingredients

Lead-free solder tin production technology selects a tin-silver-copper (Sn-Ag-Cu) alloy with a silver ratio of 0.3–4%. This alloy has the closest melting point to eutectic (Teut = 217 oC); resistance to “fatigue” and good wettability. The downside is that the shock resistance is reduced, and the cost is high. However, this disadvantage is not large and does not affect welding performance.

Synthetic process

This alloy uses the chemical reduction method with the reducing agent NaBH4 in an aqueous solution at room temperature to synthesize Sn-Ag-Cu alloy nanopowder. After the reduction is complete, a dark gray precipitate will appear at a temperature of 40 degrees Celsius for 12 hours continuously, and the alloy powder will be obtained.

Finally, this alloy powder mixture will be mixed with suitable solder fluxes to form a lead-free solder tin alloy.

This method is considered to be very easy to implement, does not require complicated equipment, and is economical. So at present, it is often used to prepare the nano-alloy Sn-Ag-Cu.

Result

Successfully fabricated solder alloy powder mixture with composition 96.5% Sn, 3% Ag, and 0.5% Cu with well-controlled content of silver and copper in the solder alloy. The powder mixture still ensures the properties of adhesion, wetting, anti-oxidation, etc. suitable for use as a soldering material in the production of electronic components. In particular, you can apply microchips in the high-tech field.

View more: Solder Wire

Above is the information about lead-free solder tin production technology that you should know. Hopefully, through the article, you have understood more about this soldering iron production technology. Currently, Thetech is a unit specializing in the production and supply of high-quality lead-free solder. If you want to know more about this product, please contact TheTech for the advice!