Basics of lead-free solder
1. Basic welding operations
① welding work purposes:
(A) mechanical connection: the two metal connection, fixed role.
(B) electrical connection, the two metal connection, the electrically conductive effects. This electrical connection is characteristic welding operations, is the glue that can not be done.
② welding operations features:
Characterized in that a welding operation can be done a lot of welding, for example by welding jet groove conducted using glue like a solder welding; Another feature is simple can be corrected.
③ definition solder:
In general, the solder is made of tin (melting point of 232 degrees) and lead (melting point 327 degrees) of the alloy composition. Wherein the solder of 63% tin and 37% lead composition is called eutectic solder, the solder melts at 183 degrees. Standard solder wire welding job uses is called rosin into the solder or wire solder. Figure ⊙, in solder flux added. This flux is a rosin and a small amount of the active agent.
The set temperature of the welding operation ④
Temperature setting is very important when the welding operation. Welding operations at the most suitable temperature is the melting point of solder used +50 degrees. The tip of the set temperature, due to the different sizes of the welded portion, the power and performance of the soldering iron, solder type and line type, on the basis of the temperature but also on the increase of 100 degrees is appropriate.
2. Lead harmful
The latest machine in the solder used, in fact, a very long history of 5000 years ago have begun to use, because the solder contains lead harmful to the environment, it may impact on the environment, so it is also changing the composition of the solder.
3. Background actual use lead-free solder

4. Lead-free solder and its problems
Table 1, the lead-free solder rosin

① tin on poor
Diffusion solder lead-free solder poor diffusion area is almost 1/3 of eutectic solder.
② high melting point
Lead-free solder melting point higher than the average of the Sn-Pb eutectic solder is about 34 to 44 degrees, the temperature setting so the tip of the soldering iron should be relatively high.

③ tip shorter life
④ oxide tip
When using lead-free solder, sometimes causing black tip surface, loss of the ability to lead, tin soldering job is aborted.
◆ tip temperature set at 400 degrees when
◆ no welding operations, electric iron energized place a long time.
◆ tip is not clean.
When the like, the situation is more prone to oxidation.
5. Precautions when using lead-free solder
① tip temperature management is important
A temperature controlled soldering iron, according to the solder used to select the most appropriate tip temperature setting is very important.
Before working with the first tip thermometer measuring the tip temperature is very important.
② Use and manufacturers (eg white tool) matching authentic tip
Counterfeit tip, aperture (put heater) are of different sizes, thickness varies sleeves which are caused by electric iron performance can not play, sometimes the cause of the fault electric iron.
③ thermal response of the thermal performance of a good electric iron, etc.
When using lead-free solder welding operation, considering the heat resistance of parts, safe operation, the tip is generally desirable to set the temperature at 350 ° -370 °.
White HAKKO942 such as good thermal response electric iron, the heater / sensor / tip integration, so that the thermal response is very good.

④ it is necessary to select the most suitable tip
The electric iron of different different welding operations, to select the most appropriate tip is very important.
The right tip can reduce the temperature of the tip, increasing the efficiency of operations.
⑤ tip of maintenance is also very important.
◆ ordinary sponge different aqueous, requires the use of impregnated additive wire, i.e., without reducing the temperature of the tip, but also can play a role in the cleaning, the tip can also remove the oxide surface.
◆ possible to set low temperature tip.
◆ 10 minutes when not in use, the power supply should be cut off electric iron.
◆ tip black oxide, first remove oxides with solder flux. If you can not be removed, first aid soaked wire cleaner to remove the oxide surface, and then coated with new solder.
■ After all the work is completed, should be painted in the new solder iron head, the welding station at collection.
⑥ improve capacity on the tin
With the use of lead-free solder, tin capacity / solder will improve diffusion.
In summary, the method is the use of lead-free solder, "as much as possible to carry out welding work at a low temperature" and "thoroughly implement the tip of maintenance," in fact, this is the basic welding job.
These are not entirely lead-free solder with technical expertise, but the traditional technology lead eutectic solder used only compare.