Electronics and Computer Systems Engineering
Student
Date
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Solder Intro Questions Answers from IPC Video 1
1. What are the two functions of a solder joint (solder fillet)?
1. Create a good electrical connection (Intermetalic Bond)
2. Create a strong Mechanical connection
2. What can be the results of incorrect solder joints?
Intermittent faults / failed equipment
3. Why should you keep your workbench clean?
a. Good housekeeping
b. Makes for easier final cleanup
c. Gives a break from the task
d. Bits of cut leads on the bench can stick to the assembly & create a short
e. Prevent contamination of the work
4. Why do we need to control static electricity in the workplace?
To prevent damage from static electricity
5. How can we eliminate static electricity?
By taking precautions
Anti-static mats, wrist straps etc
6. What type of irons do we use?
Thermostatically controlled 50Watt Iron
7. When should you use a small soldering iron tip?
When soldering small joints
Video 1 Review Answers.doc
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TAFE SA, Regency Campus
Electronics and Computer Systems Engineering
8. When should you use a large soldering iron tip?
When soldering large Joints
9. How do you choose the tip size to use?
By the size of the work to be done
Tip should be 2/3rds the size of the pad / land
10. At what temperature does 60/40 tin/lead solder start to go soft?
183̊c
11. What is the temperature of 60/40 tin/lead solder when it is completely liquid?
188̊c
In-between 183 and 188̊ the solder is in a plastic state
12. What is the melting point temperature of 63/37 tin/lead eutectic solder?
183̊c
13. What flux do we use? (Circle one)
R / (RMA) / RA / RSA
Video 1 Review Answers.doc
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TAFE SA, Regency Campus
Electronics and Computer Systems Engineering
14. What do the following letters stand for?
R
RMA
RA
RSA
Rosin
Rosin Mild Activated
Rosin Activated
Rosin Super Activated
Very Mild
Still mild but more active
Very active
Very Very Active
15. What are the 2 metals in solder?
Tin / LEAD
16. What is the advantage of 63/37 tin/lead eutectic solder?
No plastic stage
17. What is the purpose of flux?
To remove and prevent the build up of oxides
18. Describe wetting?
The ability of the solder to flow evenly over the parts to be soldered.
A good solder joint should have the solder flow to the edges of the pad, It should
be smooth and shiny with concave sides (volcano shaped).
Video 1 Review Answers.doc
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TAFE SA, Regency Campus