We are reliable and certified service provider ( factory) of PCB and PCB assembly for over 10 years. Our plant has around 5000 square meters, and has three SMT automated production lines. 2-32 layers high quality PCB. lillian yang OurPCB Tech. Ltd 008615511345900 lillian.yang@circuitspcb.com

1. OurPCB Tech. LTD
Add: 3rd Floor, Nanhai Plaza, NO. 505 Xinhua Road, Shijiazhuang, Hebei, China. 050057
Contact: Lillian Yang E: Lillian.yang@circuitspcb.com M: 0086-15511345900 SKYPE: yang.lillian10
Automated Optical Inspection (PCB AOI) in PCB design
Automated Optical Inspection (PCB AOI) in PCB design
Automated optical inspection (PCB AOI) is computer visual inspection of PCB. It is
possible to control stencil paste (size and high) and also populated component (rotation or
unplaced component). The procedure is make with a camera (one or more) and scans the
device for failure or quality defects (depends what do you want or what you will pay).
Normally it’s useful for manufacture bigger quantity; because it’s fast procedure and
quickly you can detect failure.
If you want to route and place all components for better PCB AOI inspection you have to
follow these steps:
-all PCB must be covered with solder mask color
-stencil layer may not be applicable
-take care of high component for not visible areas (shadow)
-take care of manufacture specification
Picture 1 (hidden component)
From picture 1 you can imagine what the problem is if you have to place bigger
component and use PCB AOI for inspection.

2. OurPCB Tech. LTD
Add: 3rd Floor, Nanhai Plaza, NO. 505 Xinhua Road, Shijiazhuang, Hebei, China. 050057
Contact: Lillian Yang E: Lillian.yang@circuitspcb.com M: 0086-15511345900 SKYPE: yang.lillian10
During the PCB design you have to keep in mind, which the component free area around
bigger component must be at least at component height!
Picture 2 (big component with component free area)
On picture 2 you can see reed area (component free area) on this place it’s not allowed to
place any component, because the PCB AOI camera will not see the component beside.
During the PCB design, it’s also important how to place component. On picture 3 and 4
you can check your design, and optimize it. If you decide to use PCB AOI inspection, you
have to keep in mind, to prepare PCB as it shown on picture 4! Better to see one pad on
smaller component than nothing of component. Useful information is to get the
component height; many programmes, such as Cadence Allegro, Altium, have 3D viewer,
so you can imagine the size of component, as picture 5 shows.
Picture 3 horizontal place of component

3. OurPCB Tech. LTD
Add: 3rd Floor, Nanhai Plaza, NO. 505 Xinhua Road, Shijiazhuang, Hebei, China. 050057
Contact: Lillian Yang E: Lillian.yang@circuitspcb.com M: 0086-15511345900 SKYPE: yang.lillian10
Picture 4 vertical place of component
Picture 5 – 3D viewer