How to set soldering iron temperature by manual soldering

First, the principle of manual welding:

The common manual welding process is to heat and melt the solder through a soldering iron head to connect the soldering parts (electronic components, etc.) with the pads (welded parts).

Manual welding elements: power supply (welding station or soldering iron), heating body (heating core), soldering iron head, solder, welding parts, etc.;

Second, lead-free welding knowledge

The previous solder was a tin-lead alloy such as 63/37 (63% tin, 37% lead), melting point 183 degrees. Due to the toxicity of lead to the environment, regulations such as ROHS regulations prohibit electronic products. So there is an alternative lead-free solder.

Lead-free solder is relatively lead solder:

1, the melting point rises about 34-44 degrees;

2. The tin content in the solder increases;

3, poor ability on the tin (weldability is poor), poor solder diffusion of lead-free solder, diffusion area is almost 1/3 of the eutectic solder;

Third, manual welding temperature formula:

The most suitable temperature for welding operations is the melting point of the solder used + 50 degrees. The setting temperature of the iron tip, due to the size of the soldering part, the power and performance of the soldering iron, the type of solder, and the type of wire, should be increased by X degrees (usually 100) on the basis of the above temperature. That is: tip temperature = solder melting point +50+X (loss). Such as: lead solder 63/37 commonly used welding temperature: 183 +50 +100 = 333 or so, lead-free tin copper: 227 +50 +100 = 377 degrees. Due to the effect of different product solder joint sizes, different solders, different environments and operating habits, X varies a lot here, so the soldering temperature has been used from 350-450.

Fourth, the tip loss principle:

Tip tip structure is roughly; copper - iron plated - tin plated layer, when welding, under the condition of heating, the iron plated layer will react with the tin in the solder, so that the iron is dissolved and eroded, and this The process accelerates as the temperature increases. Therefore, when the lead-free soldering is performed, the soldering temperature is generally increased and the tin content in the solder is also greatly increased, so that the life of the soldering iron tip is drastically reduced.

Five, lead-free manual welding FAQ:

1, when using high temperature, it is easy to damage the components;

2. If the soldering iron or the soldering station is poor in heat recovery, it is prone to false soldering and false soldering. The defective rate increases;

3, iron tip oxidation loss increased;

Six, lead-free manual welding common countermeasures:

1, the use of special lead-free soldering iron head (Pb-free tin plating itself, appropriate thickening of the iron plating layer to delay corrosion, extend life, while not affecting the thermal conductivity);

2. Use special lead-free soldering station (high power, rapid temperature return, which makes the temperature more stable, and can use low temperature for welding);

Seven, lead-free soldering station knowledge:

According to the welding principle, the welding process is accomplished by the transfer of heat. Therefore, lead-free soldering requires better heating efficiency of the heating body, which requires the soldering station or soldering iron to have greater power and faster thermal recovery. Practice has proved that the power of lead-free soldering stations commonly used in the market is more than 90W. Compared with the previous 60W soldering station or single soldering iron, the thermal efficiency and thermal recovery have increased a lot, so when welding the same products, the required welding The temperature will be 10-30 degrees lower and more stable. This matched with a special lead-free soldering iron head, the loss of the iron head is also greatly reduced, while the cost is reduced, the product quality has also been guaranteed.