Drilling Parameters

About Drilling Parameters

Parameters for drilling and slot drilling, conditions for Drilling in the chart are available.

Hits, number of repoints and stack heights are for general information. They should be determined by hole quality.
Where the board thickness and/or stack height are not shown in the table, please contact Union Tool's Technical support team
These parameters can be affected by the condition and performance of both the spindle and drilling machine.
The pressure foot and vacuum performance of the drilling machine can affect hole quality.
Periodic inspection, maintenance and measurement is strongly recommended.
The thickness of the entry and back-up board, together with the material type can affect the drilling parameters and care should be taken to choose and appropriate product.
More detailed information can be found in each parameter file.

Terms	Major units	Meanings and formula
Spindle speed	rpm	Number of revolution per minute
Velocity	m/min mm/sec Inch/min(IPM) Feet/min(SFM)	Velocity of periphery V=π·D·N / 1000 V: Velocity [m/min] D: Drill bit diameter [mm] N: Number of revolution per minute [rpm] SFM: Surface feet per minute 1m/min = 3.28 Feet/min
Infeed rate	m/min mm/sec Inch/min(IPM)	Vertical speed of drilling
Chipload	µm/rev Mil/rev	Feed amount per revolution f =F/N x 1,000,000 f :Chipload [µm/rev] N:Number of revolution per minute [rpm] F:Infeed rate [m/min]
Retract rate	m/min mm/sec Inch/min(IPM)	Retract speed after drilling
Depth into back-up board	mm Inch	Penetration depth into back-up board. Too Shallow causes a risk of not drilling through the PCB. And too deep can cause registration accuracy, roughness, and breakage problems.
Hits	-	Life of drill bit. This parameter table shows the general values inputted into drilling machine.
Repoint (Number of repoints)	-	Generally, the tip of drill bit is repointed after use, having deteriorated through wear. This parameter table shows the general information for repointing frequency.
Stack height	-	To improve productivity the PCB is often stacked up for drilling. This parameter table shows the general number of panels per a stack for each general PCB thickness.

Distance	1m = 1000mm = 39.37Inch 1Inch = 0.0254m = 25.4mm
Velocity, Infeed rate, Retract rate	1m/min = 16.67mm/sec = 39.37Inch/min = 3.28Feet/min(SFM) 1mm/sec = 0.06m/min = 2.36Inch/min 1Inch/min = 0.0254m/min = 0.423mm/sec
Chipload	1µm/rev = 0.0393Mil/rev 1Mil/rev = 25.4µm/rev