Normally the pcb board is showed as single Pcs in drawing after design, however, pcb manufacturer won't always make PCB as single pcs in the production, because usually PCB assembly process require panelized PCB to improve efficiency, and if the pcb board is special small with irregular outlines, this will be difficult for pcb manufacturing process
as single pcs, we need to panelize these pcb before production, which will be helpful to shorten pcb manufacturing lead time, it will be also easy to control quality and count PCB quantity before shipment.
1. Panelization with break-away but without spacing between each single Pcs, this is the most common way, generally, it is popular to most customer if customers do not have special requirements on PCB outline and PCB bur after profile, normally use V-cut to separate the pcb boards as single pcs, but sometimes these single pcs will have slight bur, but it's also easy to polish the bur and will not influence PCB function, on the other hand, the break-away is helpful for the boards to fix on the machine and strengthen the whole array.
2. Panelization with break-away, and spacing between each single Pcs. If customers have special requirements on PCB outline and board edge without bur existing, in that case we have to use the profile of routing, thus, it requires spacing between each single board, generally the spacing is within 1.5~2mm, This will be helpful to control the bur.
3. Panelization without break-away, which is convenient for shipment, but not helpful for follow-up process, there are a few customers need to do assembly by manual, if so it's feasible to use panelization without break-away, this kind of panelization will save the cost for board edge and make cost down properly.
4. Panelization with stamp holes, the stamp hole is the small holes to connect single boards, these holes look like stamp sawtooth, so it's called stamp hole connection. pcb manufacturers could use stamp hole connection to control and reduce burs, so the stamp holes can be used to replace V-CUT.
Statement: This post is only the personal view of the author and does not represent the opinions of ALLPCB.com.