The PCB board is generally glued together by several layers of resin material, and the internal copper foil is used for wiring, and there are 4, 6, and 8 layers. Among them, drilling occupies 30-40% of the cost of printed circuit boards, and mass production often requires specialized equipment and drill bits. Good PCB drill bits use good quality cemented carbide materials, which have high rigidity, high hole position accuracy, good hole wall quality, and long life.

There are many factors that affect the hole position accuracy and hole wall quality of drilling. This article will discuss the main factors that affect the hole position accuracy and hole wall quality of drilling, and propose corresponding solutions for your reference.
Why is the Fiber Proturusion in Hole protruding?

1. Possible reason: the retracting rate is too slow.

Countermeasure: Increase the speed of retreating the knife.

2. Possible cause: excessive wear of the drill bit

Countermeasures: sharpen the drill point again and limit the number of hits per drill point, such as 1500 hits on the line.

3. Possible reasons: insufficient spindle speed (RPM)

Countermeasures: adjust the feed rate and rotation speed to the best condition, and check the rotation speed variation.

4. Possible reason: feed rate is too fast

Countermeasure: Reduce the feed rate (IPM).

Why are Rough hole walls?

1. Possible reason: the feed amount has changed too much.

Countermeasure: Maintain a fixed feed amount.

2. Possible reason: feed rate is too fast

Countermeasures: Adjust the relationship between the feed rate and the drill speed to the best condition.

3. Possible reason: improper selection of cover material

Countermeasure: Replace the cover material.

4. Possible reason: insufficient vacuum used for the fixed drill

Countermeasures: Check the vacuum system of the drilling machine, and check whether the spindle speed changes.

5. Possible reasons: abnormal retraction rate

Countermeasures: adjust the relationship between the retraction rate and the drill speed to the best condition.

6. ​​Possible reasons: the cutting front edge of the needle tip appears to be broken or broken

Countermeasures: Check the condition of the drill bit before getting on the machine, and improve the habit of holding and taking the drill bit.

Why the roundness of the hole shape is insufficient?

1. Possible reason: the spindle is slightly bent

Countermeasure: Replace the bearing in the main shaft (Bearing).

2. Possible reasons: eccentricity of the drill tip or different widths of the cutting edge

Countermeasures: Check the drill bit with a magnification 40 times before getting on the machine.

Why are there crimped debris with broken lotus roots found on the board surface?

1. Possible reason: the cover is not used

Countermeasure: add a cover plate.

2. Possible reason: improper drilling parameters

Countermeasures: reduce the feed rate (IPM) or increase the drill speed (RPM).

Why is the drill pin easy to break?

1. Possible cause: excessive run-out of the spindle

Countermeasure: Try to deflect the main shaft.

2. Possible reason: improper operation of the drilling machine

Countermeasures:

1) Check whether the pressure foot is blocked (STIcking)

2) Adjust the pressure of the pressure foot according to the condition of the drill tip.

3) Check the variation of the spindle speed.

4) Drilling operation time to check the stability of the spindle.

3. Possible reason: improper selection of drill bits

Countermeasures: Check the geometry of the drill bit, check the drill bit defects, and use a drill bit with an appropriate chip recess length

4. Possible reasons: insufficient drill speed and too high feed rate

Countermeasure: Reduce the feed rate (IPM).

5. Possible reasons: the number of laminate layers increased

Countermeasure: Reduce the number of layers of the laminated board (Stack Height).