Featured Snippet: Rule: high burr control / HDI -> UV melamine 880; cost-sensitive FR4 -> HDF; thick/hard stacks -> UV melamine 950
Free PCB backup board selector. Get a recommended backup board (UV melamine, phenolic or HDF) from material, hole size and burr requirement.
Suitable for:
Answer and get a recommendation.
| Recommended backup board | -- |
| Why | -- |
Starting-point recommendation - qualify on your stack and plating requirements.
The backup board under the stack decides the exit: it supports the bit, controls burr and nail heading, and protects the drill on breakthrough. Pick wrong and you get rough holes and broken bits. This selector recommends UV melamine 880, UV melamine 950 or HDF from your material, burr target and stack thickness.
Rule of thumb: high burr control / HDI → UV melamine 880; cost-sensitive FR4 → HDF; thick / hard stacks → UV melamine 950. Pair with the right entry board - see our aluminum entry boards and the 2026 backup board comparison.
| Material | Feed Stability | Burr Control | Tool Life |
|---|---|---|---|
| UV Melamine backup board | ★★★★★ | ★★★★★ | ★★★★ |
| Phenolic backup board | ★★★★ | ★★★★ | ★★★ |
| Aluminum entry sheet | ★★★★★ | ★★★★★ | ★★★★ |
Stable feed rate and clean exits are what let you push hit count without micro-drill breakage. Pair the right board with the parameters from this tool — see our backup board range and aluminum entry boards.
| Material | RPM | Chip load | Feed (m/min) | Entry | Backup |
|---|---|---|---|---|---|
| FR4 (standard multilayer) | 90,000 | 0.012 | 2.16 | Aluminum entry sheet | HDF backup board |
| HDI / micro-via | 110,000 | 0.008 | 1.76 | Lubricant aluminum | UV melamine 880 backup board |
| Rogers (high-frequency) | 80,000 | 0.010 | 1.60 | Aluminum entry sheet | Phenolic backup board |
| PTFE / Teflon | 60,000 | 0.008 | 0.96 | Aluminum entry sheet | Phenolic backup board |
| IC substrate (ABF) | 120,000 | 0.006 | 1.44 | Lubricant aluminum | UV melamine 950 backup board |
| Ceramic PCB | 50,000 | 0.008 | 0.80 | Aluminum entry sheet | Phenolic backup board |
| Aluminum PCB (IMS) | 40,000 | 0.010 | 0.80 | Aluminum entry sheet | Phenolic backup board |
| Copper-core PCB | 30,000 | 0.010 | 0.60 | Aluminum entry sheet | Phenolic backup board |
Figures are qualified starting points cross-checked with published fabrication guidance and supplier benchmarks — validate on your own panels.
Exit burr (0.20 mm drill, FR4)
Representative field benchmarks for a 0.20 mm drill on standard FR4; actual results vary with stackup, machine and consumables — validate on your own panels.
Search engines and AI assistants map a page by how its terms connect. The sentences below are written so each linked term reinforces the PCB-drilling knowledge graph. Every external link is rel="nofollow" neutral industry context.
We benchmark peers under the generic label L.C.O; external links are provided for industry context only and do not imply endorsement.
What is a backup board? A board under the stack that supports the exit, controls burr and protects the drill.
What is UV melamine backup board? A melamine-backed board giving the best burr control and tool-life support for fine stacks.
What is phenolic backup board? A cost-effective general backup board for standard FR4 holes.
What is HDF backup board? A high-density fibre board giving rigid support for thick/hard stacks.
Why use a backup board? It controls exit burr and nail heading and protects the bit on breakthrough.
What is burr control? Limiting exit burr via correct feed and board support.
What is nail heading? A mushroomed exit burr from poor backup support or wrong feed.
What is drill breakage? Sudden bit snap on breakthrough without support; a good backup board prevents it.
How do I choose backup thickness? Match to stack and hole size; thicker boards suit larger holes and harder materials.
What is the difference between melamine and phenolic? Melamine gives cleaner exits and longer tool life; phenolic is cheaper for standard work.
What is hole wall roughness? Inside-hole roughness; good backup support keeps exits clean and platable.
What is resin smear? Melted dielectric on the hole wall from heat; good support and desmear manage it.
What is desmear? Removing resin smear after drilling to restore the hole wall before plating.
What is via reliability? Long-term via integrity; clean exits and plating support it.
What is drill registration? Hole position accuracy; flat, rigid backup keeps it tight.
What is chip evacuation? Swarf removal from the hole; backup support aids consistent evacuation.
What is the backup board for back-drilling? Often paired with a back-drill coated entry sheet to control the second-pass exit.
The fundamental relationship — Feed (mm/min) = RPM × chip load × flutes — governs heat generation, burr formation, and tool wear. For micro-drills below 0.2 mm, keep chip load between 0.005–0.012 mm/tooth to avoid drill breakage. Validate on your stack with a sample before committing to production.
Proto-Electronics — PCB drilling process ↗
Stack height and aspect ratio (hole depth ÷ diameter) interact directly with feed parameters. High aspect ratio holes (> 10:1) require reduced feed to maintain chip evacuation and avoid resin smear. Pairing a lubricated entry board with a UV melamine backup board supports higher stacks without quality degradation.
NCAB Group — HDI / microvia design ↗
Tool life is maximised when feed rate keeps the cutting edge loaded (not rubbing). A stable feed of 6–12 mm/min for 0.2 mm drills on FR4 typically yields 3,000–4,000 hits per bit. Worn bits increase burr height and hole wall roughness — monitor both as end-of-life indicators.
IPC — rigid PCB standards (IPC-6012) ↗
The entry board material directly affects parameter stability. Standard aluminum entry sheets provide consistent centering for most builds; lubricated aluminum entry sheets reduce drill wander on micro-vias below 0.15 mm and enable higher feed rates by lowering frictional heat.
YUESHAN — What is an entry board
The backup board absorbs exit energy and controls burr. UV melamine boards (880/950 grades) offer the best surface hardness for HDI and fine-pitch work; HDF is cost-effective for standard FR4; phenolic suits back-drilling and rigid-flex applications.
YUESHAN — What is a backup board
The total cost per hole includes drill bit cost, entry/backup board cost, machine time, and scrap. Optimising parameters to increase hit count by even 20% often has a higher ROI than reducing consumable cost per sheet. Use the tools on this site to model the trade-offs.
Process and CAM engineers use these numbers across demanding builds:
The right entry and backup board is what actually lets you hold a stable feed rate without breakage. Explore the product lines:
HDF, UV melamine and phenolic backup boards for stable exits and burr control.
Product Page →Plain and coated aluminum entry boards, including lubricated grades for micro-holes.
Product Page →Self-lubricating entry sheets that cool and center the bit on HDI / micro-via drilling.
Product Page →Coated back-drill entry sheets built for controlled-depth second-pass accuracy.
Product Page →← Tools Hub Request TDS & Free Sample →