Hybrids given automated QA tests

Citation

(2000), "Hybrids given automated QA tests", Assembly Automation, Vol. 20 No. 2. https://doi.org/10.1108/aa.2000.03320baf.005

Hybrids given automated QA tests

Hybrids given automated QA tests

Keywords: Solenoid, Car, Production

The introduction of so-called smart solenoids into the latest specification of car alarms, has necessitated the adoption of a new set of exacting test regimes for the hybrid board on which they are based. For this purpose, Tamworth-based CPR Automation Ltd has designed and constructed a novel production line that is capable of automatically handling a variety of test regimes for boards of this type (see Plate 6). Adding further complexity to the test procedure, although each hybrid has the same external package, internally the circuitry differs according to the vehicle to which it eventually will be fitted. So, the process has had to be configured to suit a variety of end users.

The line, which occupies only 2m x 2m floor space in a clean room, was commissioned by a major supplier to the automotive industry. Its function is to pass each hybrid through a series of test stages involving: a pin alignment test; heating to 125°C + 5°C; functional test; inkjet printing of barcode; verifying the barcode as correct; cooling to ambient temperature; and, finally, placing the hybrid board into a transport package.

Plate 6CPR Automation Ltd has designed and constructed a novel production line

In view of the specialist nature of the hybrid board and its test parameters, CPR's customer elected to produce the functionality test equipment in house. This left CPR engineers the task of integrating it seamlessly into the conditioning, marking and packing line.

The hybrid packages are delivered directly to the line from an hermetic test stage. After which they are passed automatically through all the stages of the process and finally placed into the correct storage tray. The only operator involvement is to load empty trays to the packing area of the line and unload them when they are packed.

At the start of the line, the hybrid boards are collected from a chute by means of a simple handling device, in the correct orientation. They are then transferred to a walking beam mechanism which conveys them through a set of heating blocks to raise their temperature to 125°C þ 5°C.

Having reached the correct temperature, the hybrid packages are moved from the heating area by the walking beam transfer unit to the test station. Here, a linear slide locates a set of spring-loaded, gold-plated, test probes against the pins of the package. A non-conducting back stop is provided for the pins to counteract the bending forces exerted by the probes and so prevent damage. The back ends of probes are attached to a set of flying leads for connection to the test equipment.

The line is capable of providing up to 400 tests/hour and the final result for each hybrid board - pass or fail - is stored on a simple mechanical data tag attached to the walking beam transfer arm and read at the inkjet/reject station. It is used to trigger either the printing of a barcode on the board or its ejection from the line.

Use of a simple mechanical data tag has several significant benefits. First, it allows the test result to be stored, even if the power supply has failed, and can be read, without loss of memory, when the power has been restored. It also permits the result to be seen and verified by machine setters and technicians and allows the barcode reader/reject arrangement to be separated from the test area, thereby simplifying the mechanical arrangement of the test station.

When the hybrid packages have been tested and coded, they are cooled to ambient temperature by passing them through a cooling section. They then enter the packing and storage station which occupies two zones situated on either side of the walking beam. A storage tray is mounted in each zone and is populated by means of an X-Y robot arm which fills one tray then cycles to the other zone. The storage trays are manually loaded and unloaded into the two zones and, in normal operation, one tray is available for the operator while the other is being automatically filled. A visual indicator is illuminated to alert the operator that a tray has been filled and is ready for changing.

For further information, please contact: David Riley, CPR Automation Ltd, 7 Apollo, Lichfield Road Industrial Estate, Tamworth, Staffordshire B79 7XH, UK. Tel: +44 (0) 1827 57475; Fax: +44 (0) 1827 62354; E-mail: CPRAutomation@dial.pipex.com