Where Every PCB Begins: Mechanical Drilling
The CNC drilling machine is the first piece of equipment to touch a blank PCB panel. Before imaging, before plating, before any circuit pattern exists — the drill creates the holes that will become vias, component leads, and mounting points. The quality of this first step determines success at every subsequent process station.
Our workshop operates a fleet of high-speed CNC drilling machines including Taiwan Tongtai SD-62C 200,000 RPM drilling machines (2 units) alongside Hitachi, LongZe, and DongTai platforms. Together they provide 150+ spindles capable of drilling holes as small as 0.15mm (6 mil) with positional accuracy of ±25μm — one-quarter the width of a human hair.
Drilling Capability at a Glance
| Parameter | Specification |
|---|---|
| Minimum drill diameter | 0.15mm (6 mil) |
| Maximum aspect ratio | 20:1 (e.g. 0.2mm hole through 4.0mm board) |
| Positional accuracy | ±25μm |
| Spindle speed | 160,000–200,000 RPM |
| Maximum panel size | 610mm × 760mm (24" × 30") |
| Drill bit types | Solid carbide, diamond-coated for abrasive materials |
| PPTX Actual equipment photo | Taiwan Tongtai SD-62C 200,000 RPM drilling machine (2 units) |
The 0.15mm minimum diameter supports high-density interconnect (HDI) designs where laser-drilled micro-vias are combined with mechanical through-holes — the standard architecture for modern multilayer PCBs used in 5G base stations, automotive ADAS modules, and enterprise networking equipment.
Why Drill Quality Defines Board Reliability
Plating Adhesion. A cleanly drilled hole with minimal resin smear exposes clean copper on the inner-layer capture pads. Electroless copper bonds directly to this surface, forming the foundation of a reliable plated through-hole. Poorly drilled holes leave resin residue that blocks copper-to-copper bonding — the most common cause of intermittent opens in multilayer boards.
Registration Budget. Drill position accuracy directly affects annular ring requirements. IPC-6012 Class 3 requires a minimum 25μm annular ring. A drill positioned 40μm off target consumes the entire tolerance before any other process variation is considered. Our ±25μm accuracy preserves the annular ring budget for subsequent processes.
Impedance Control. For controlled-impedance designs, the drilled hole diameter — and the plated hole diameter that results — is part of the impedance model. A hole drilled oversize changes the via stub length and parasitic capacitance, degrading signal integrity at high frequencies.
Drill Bit Management: The Competitive Edge
Drill bits are consumables measured in cents. But how you manage them separates high-yield from low-yield PCB fabrication. A worn drill bit produces burrs, resin smear, and rough hole walls. It also runs hotter, accelerating wear on subsequent hits.
Our drill bit management system tracks every bit by hit count. Standard FR-4 bits are replaced after 2,000–3,000 hits. High-Tg and halogen-free materials — which are harder and more abrasive — trigger replacement at 1,500 hits. Bits used on PTFE-based RF materials (Rogers, Taconic) are replaced even more frequently due to PTFE's tendency to smear and clog flute geometry.
The economics are clear: a drill bit that costs $0.30 can ruin a $300 panel. We manage both ends of that equation.
On the Production Floor
The drilling workshop operates 24/7 during peak production. Panels are stacked in pinned drill bushes — typically 2–3 panels per stack for standard FR-4, single-panel for high-aspect-ratio or tight-tolerance jobs. Entry and backup materials (aluminum entry sheet, phenolic backup board) are used on every stack to ensure clean entrance and exit holes. After drilling, every panel is deburred mechanically and inspected under magnification before proceeding to the desmear and plating processes.
For PCB designers pushing the limits of hole density, aspect ratio, or positional tolerance, our drilling workshop has the spindle count, the precision, and the process control to deliver — starting with the very first physical step in PCB fabrication.
