Block Assignment: Modules 4-6
A lead (40%) – tin alloy that is cooled from 300 degree C to room temperature starts as a liquid and ends as a solid.
- Describe the stages and composition of the grains and their size if cooled fast or slowly.
Provide essay answers with a maximum of 500 words. Use current APA format for all references.
Modules 4-6 Forum
An electrical component needs to be soldered into a circuit board. It is a safety critical component and therefore must not suffer from classic soldered problems. In your initial post respond to the following questions: What composition of solder (percentage of lead and tin) would you select and justify why? In addition what would be the typical micro-structure and possibly induced solder process problems?
In order to write your initial post, you will be choosing one option from each of three categories. First, you will choose a type of switch, then you will determine how your circuit board will be manufactured, and then you will determine the specific purpose of the circuit board.
Your answer will depend on selecting one option from each of the three lists below.
Carefully weigh the pros and cons of each switch type. Do your research to determine which one will work best for the application you choose. Module 1 Heads-Up: Technical Report has references for the transistor switches.
- Transistor (NPN or PNP)
- Mechanical switch.
Circuit Board Manufacture
Once you know what type of switch you want to use, you need to decide on how your circuit board will be manufactured.
Will it be made by hand, will it have fully automated assembly, or will it be small batch manufacture? Each of these has their unique aspects. For example, mass production, any error will be repeated. Manually, an error is probably human and the chances of propagation are lowered.
- Prototype circuit board made by hand
- Fully automated assembly
- Small batch less than 1000.
Circuit Board Use
Finally, what will the circuit board be used for?
- Fighter jet
- Military transport
- Medium commercial airliner