Hardware Verification and Validation
What makes a hardware product good is testing. Almost all designs are very similar in the architecture but their performances varies greatly
The main goal for testing is to ensure a high quality bar for the product in the areas of functional, performance, and reliability.
Product testing Stages
There are three main progression of testing during a product development cycle.
In order to unlock any development by other technology teams (e.g RF, power, sensors, thermal, reliability etc.), the electrical engineers have to firstly make sure the device is can be powered on and software can be loaded and ran.
When the very first board comes into the lab, the EE needs to work hard to bring up the device into a ready state, and this initial test step is called bring up.
During the bring up, EE makes sure the device has the correct components mounted with right orientation on the PCB, no short or open circuits are detected, correct power on/off sequence, correct voltage regulator outputs, all digital interface works, and all subsystem can be read and write to.
After bring up is done, the EE moves validation stage, the goal of this stage is to ensure long term reliability of the electrical system. Tests like signal integrity and current leakage, etc are done by EEs. Power engineers will make sure power integrity of the power rails powering digital, analog, and RF components are within specification. In addition they make sure components are sized correctly to excess power draw does not damage the power system. Similarly, the thermal engineers make sure the product surface/skin temperature is within a safe limit under worst case conditions.
This is the last stage of testing. Successfully passing a compliance test certifies your product that can be sold in the market. This includes FCC emission and UL safety tests. EE works with compliance team to adjust the designs to ensure safety limits are met.
Summary & Conclusion
We provide a quick view of what are the 3 main steps to hardware testing, bring up, validation, and certification before a product can be safely shipped to end users.
In conclusion, testing is a vital part of product design and often takes the most of time to ensure the design is done correctly. Test and design change iteration is what consumes a majority of an engineer's daily routine.