What are the considerations during product assembly and manufacturing automation?


Factory Automation.

Product Assembly
Product assembly process should be considered early in design stage.For environmental
recycle purpose, one sub-assembly parts that is difficult to separate
in disposal should use same type material as possible. The assembly
method should be selected for easy assembly operation, enhance higher yield,
and product repairable consideration.
PCB jumper : For saving manpower, using 0-ohm resistor (0805 or 1206 size)
as jumper is better than using wire jumper.
PCB subassy : PCB subassembly better design capable for individual testing
before casing assembly process.
PCB pads : Consider to have connection pads on PCB for software upgrade and
PCB testing purpose.
Screw : Use plastic snap fit can save screw mounting time and more efficient
for repair-free product. If product yield is low that there is repair chance, screw
gives flexibility in touch up process. Screw can give better rigidity and security
to the product under drop test.
IR diode : IR diode location should be design with internal support that cannot
be easily dislocated during assembly process.
Foolproof : If the assembly parts are easily misinterpreted by the human operator
during process, then needs add foolproof design in the part for easy assembly
process. Such as use different length screw that can be easily identified
visually, use 4mm and 6mm lengths instead of 4mm and 5mm screw.
Manufacturing Automation
? Automated robots have been deployed in electronics manufacturing in any
stage of entire production cycle. Application areas include component fabrication,
pick and place, assembling miniature components on PCBs, applying
adhesives, carryout inspections and testing, and product packing.
? Although automation needs high initial setup cost, it can reduce the labor
costs while increasing the production times and reducing errors and wastage.
? Automated robot can adapt to different product design with adequate fixtures
and programming.
Followings are some examples for production automation machine:
? Injection machine robot arm
? It is installed with injection machine for repeatable taking out the fabricated
plastic part and place in adequate location.
? Relatively low initial cost.
? SMT Pick-and-place machine
? It uses to place electronic components onto PCB before reflow soldering.
? It can handle tiny component size as 0201 or 0402 that difficult handled by
human operator.
? ICT (In-circuit tester)
? ICT is the most robust type of PCB testing at high initial cost.
? It powers up and actuates individual circuitry on the board for test that have
85-90% coverage of PCB.
? There are access points predesigned in the PCB that allows the ICT testing
probes to make connections with the circuit.
? It is for a “mature” product with very few revisions expected.
? Flying Probe tester
? Flying probe testing is less expensive than ICT.
? It does not power up the PCB for testing.
? It can test PCB circuitry for Opens, Shorts, Resistance, Capacitance, Inductance,
Diode issues.
? It uses needles attached to a probe on an x-y grid to contact on the PCB
and runs the testing program.
? AOI (Automatic Optical Inspection) Machine
? It uses 3D camera to take photos of the PCB and then compares the photos
with the standard PCB in detailed schematic.
? It is non-contact type inspection.
? It should combine with other functional testing method, such as ICT.
? Remote Control Auto Tester, It can provide testing on the following remote
control functions
? Key activation function
? Standby Current
? Operation Current
? Operation test at low voltage
? IR transmission power
? Some models can also perform testing on RF power, such as Bluetooth, and
MAC reading
? Automatic Assembly
? Generally, Assembly line is operator intensive with some semi-auto machine
in accomplish the task, such as pneumatic screw driver, auto glue
dispenser, and pneumatic fixtures.
? For advance automatic assembly, it involves using robots which is more
justify for high volume production.
? Some factories developed auto casing assembly machine that remote is designed
with snap fit without using screw and only minimal human operation
are required.