Sometimes we need special holes in PCB for mechanical purpose, like Countersink hole, Counterbore hole, Press fit hole etc, today we - China PCB manufacturer will introduce Countersink and Counterbore hole in PCB.
Countersink hole
A countersink hole is a cone shaped hole cut into the laminate. It is typically used to allow the tapered head of a screw to sit flush with the top of the laminate. By comparison, a counterbore makes a flat-bottomed hole and its sides are drilled straight down. This is usually used to fit a hex-headed cap or screw.
Generally, PCB manufacturers need the following information to drill a countersunk hole.
Angle of the drill
Major Diameter (finished diameter of the hole at the surface)
Depth the countersink is to be drilled
On which side of the board is the sink? Top or Bottom?
The finished diameter of the shaft of the hole
Is the sink and shaft to be plated or non-plated?
PCB countersink hole
Counterbore
A counterbored hole is typically used when a fastener such as a bolt or cap head screw is required to sit flush with or below the level of a surface.
Generally, PCB manufacturers need the following information to drill a Counterbore hole.
Major Diameter (finished diameter of the hole at the surface)
Depth the countersink is to be drilled
On which side of the board is the sink? Top or Bottom?
The finished diameter of the shaft of the hole
Is the bore and shaft to be plated or non-plated?
Because the sides of the hole are always parallel, there is no need to specify an angle.
PCB Counterbore hole