soldering

Hi , I have this question to answer in an assignment I have no practical experience in soldering the question is, The solder used when manually assembling an electronic appliance must have a ,
A) Chemical coating
B) Low tin- lead ratio
C) very high melting point
D) high tin - lead ratio

25 watts soldering irons are currently using by most of the electronics lovers and workers because higher power soldering irons may burn electronic components due to the overheat and the question u asked is not about practical things

lecto said:

Hi , I have this question to answer in an assignment I have no practical experience in soldering the question is, The solder used when manually assembling an electronic appliance must have a ,
A) Chemical coating
B) Low tin- lead ratio
C) very high melting point
D) high tin - lead ratio

Click to expand...

Considering each point of this very badly worded "assignment", (I dont think your teacher has any practical experience in soldering either!).

A) Chemical coating.
Solder for electriical and electronic use has chemically active flux INSIDE, not outside.

B) Low tin- lead ratio, D) high tin - lead ratio.
The traditional solder for electronics work has around 60% tin and 40% lead, some solders have 63% tin (hint: Google "eutectic point in solder" ).

C) very high melting point.
The melting point is determined by the tin/lead ratio.

With the introduction of lead-free solders in recent years, most solders used in electronics have no lead in them at all.


JimB

Ziddik said:

25 watts soldering irons are currently using by most of the electronics lovers and workers because higher power soldering irons may burn electronic components due to the overheat and the question u asked is not about practical things

Click to expand...

Is the worst, most ill informed and just plain wrong answer I have seen here on ETO in a long time.

JimB

Hi! The answer is D.... A ) chemical coating ?? B) most rework solders are not mostly lead. C) high melting point solders are normally found in flow solder machines

D) most solders (as JimB said are 60%+ tin 40% lead) newer tin silver solders are a b***er to work with.....However agreeing with JimB again its a badly worded question as due to ROHS legistration we're not supposed to use tin/lead anymore.

Ian

Ask your instructor what RoHS means.