4.2 Printed Circuit Boards Flashcards
(14 cards)
What is the job of a printed circuit board?
It physically supports the components and contains the wiring within he board
What is the first step in producing a printed circuit board?
A process called patterning (converting a circuit diagram into a pattern for the components)
What is the second step of producing a printed circuit board?
Printing the pattern onto the board
What are the two methods of printing onto a printed circuit board?
-etching method
-addition method
How does a single sided printed circuit board work?
The ‘wiring’ on one side and the components mounted on the reverse side
When is a double sided printed circuit board used?
When a more complex circuit is needed and components can be on both sides without ‘wiring’ connecting
What is the main disadvantage of multi-layer circuit boards?
The internal planes act as heat sinks
What are flexible circuits made from?
Mylar or Kapton
What is surface mount technology for printed circuit boards?
When the component uses the solder joint to form a mechanical and electrical connection (no through holes or terminals needed)needed)
What is conformal coatings?
Transparent liquid film applied to the conductors of a printed circuit board
What are the benefits of applying conformal coatings to the circuit boards?
Protection against;
-moisture
-humidity
-shock
-vibration
-corrosion
-electrical isolation
What three ways are printed circuit boards or cards utilised on aircraft?
-fitted inside boxes or components
-fitted into rack assemblies
-fitted into computers
What is an LRU?
Line replaceable units
