Question 1

Why does V-CUT will be added during PCB design?

Accepted Answer

Because the strength and hardness of PCB.
After finishing the pc board assembly, in order to fit the PCB into the end product. The PCB manufacturer will design V-Cut to de-panel the PCB
Those dividing lines that were cut by cutter on the PCB is called V-CUT and it is commonly seen between break-away rail and unit on PCB.
It is literally impossible to de-panel PCB with your hands.
Even if you do break the PCB manually, the electronics circuit board parts will be damaged.
When bending the PCB, the application of the force will cause PCB deformation which might result in the electronics circuit board parts cracked.
If thickness of PCB is too thin, we do not suggest to do V-CUT because it will damage PCB structural.

Question 2

Why does long stored PCB need to be baked before assembly or running through reflow oven?

Accepted Answer

The purpose of baking is to remove the moisture from the PCB.
No matter the PCB is at production site or still in vacuumed package, both would increase the risk that PCB can absorb moisture.
If PCB is stored at a bad storage condition or over storage period, these would also make the PCB absorb moisture easily.
The high temperature would cause inner board moisture evaporation when assembly the damp PCB.
The PCB will have blister or delamination due to steaming.

Knowledge