Board Lifecycle

1

ideas/questions to ask yourself:

1. what will it interact with?

2. can we integrate this into another board/do we need this function?

2

create a block diagram of the board:

1. this helps visualize the power and signal paths and you get a better idea of how the board will work

2. helps others understand your board and easier during debugging

3

component searching:

1. **important - need to be able to get the components designed with to ensure they work

4

schematic design:

1. follow your block diagram

2. add notes

3. use net classes for high power nets

4. include test points (these need be designed into the board)

5

design calculations and documentation

1. understand all of the components on the board and their purpose

2. useful for debugging

3. use simulation tools to test the circuit and measure the current and voltage (ltspice is good – a lot of spice simulations come with the components on digikey of they are used a lot)

6

layout and routing

1. place your components neatly

2. make sure you have access to components

3. label testpoints

4. others do not know your board that well so it be easy for them to identify what plugs into where and in which order

5. how will the board fit into the car

6. keep in mind: mounting holes, board bending, vibrations

7

test plan

1. test to make sure it meets the requirements

2. figure out what harnesses are needed for testing equipment (oscilloscope, power supply, dmm clips, signal generator)

8

gerbers

1. send board to manufacturers in the format of gerber

2. double-check the output with an online gerber viewer and open the file with altium to view one at a time

9

manufacturing

1. panelization of smaller boards

2. manufacturers do not like too many vias

3. multi-layer boards are pressed together from the individual layers

10

assembly/bringup

1. soldering:

   1. stencil and reflow - solder paste goes through the openings in a laser cut steel sheet to stick to the board

   2. hand soldering

2. component placement

   1. manual placement using tweezers

3. inspection

   1. visual inspection of solder joints

11

cleaning

1. electrical paths can grow between board layers if contaminants are left on the board

2. flux is good for soldering, but ‘activate’ it with heat since it is a primary source of contaminants

12

hardware testing and validation

1. does the board do what it is designed to do?

2. measure voltages and signals

   1. figure out what the expected result is first

3. connecting oscilloscopes, thermocouples

4. simple programming

   1. measure pin-outs and communication busses

13

firmware and integration testing

1. the board has to fit with the rest of the car

2. firmware needs to be able to produce the expected output

   1. help them understand the board (working principles, design intent, expected output)