End Of Line testing stations are used at the end of production lines to test if the manufactured product, as it is going to be delivered, meets its specifications. To solve this task the solution tends to be very tailored for the device in question. For the bulk of the production it is also the last time it is inspected and checked, any failure that passes will have an impact in the customer.
The typical test station for a manufactured product will check different parameters, and generate some data that will go into a database, print some labels or barcodes and produce some kind of PASS - NO PASS signal.
An important factor in their design is the production volume, because it might bring in quite an amount of mechanical automation, which can be cost effective over manual testing.
Both projects described below were designed to verify the tests at every step, with full traceability and logged results to a database allowing the analysis of the different failure modes.
Case 1: RF Test Station
Test station for radio modems.
- Designed and implemented the software and custom hardware.
- Test software was divided in two parts, one running in a PC based test rig and another part running in the device under test.
- Detection and analysis of RF for testing the device's transmitter, with full characterization of parameters (power, frequency deviation, bandwidth, etc.).
- Generation of RF signal to test the device receiver, again with full characterization of radio parameters (gain, bandwidth, etc).
- Quality assesment of key components as the oscillator quartz and the radio transceiver.
In this case, due to the small volume, the device test was performed by manual insertion in the test station.
Case 2: Hall Sensor Test Station
Test station for hall sensors used in automotive applications.
The characterisation was completely done in the test station. Due to the manufacturing volume the tests involved were fully automated with:
- Servos
- Pressurized air actuators
- Light barriers
- Cameras with shape recognition
- Minimal operator interaction
The work involved adapting an existing software framework to new sensors, actuators and tests for the new production device.