What Is an Aluminum Entry Board?
An aluminum entry board, also called a PCB entry sheet, aluminum entry sheet or drill-entry sheet, is the top consumable layer in a mechanical PCB drilling stack. The drill touches this sheet before entering the copper and laminate beneath it.
This page is the commercial product hub for YUESHAN plain AA1100 H18 entry sheets. For alloy chemistry, temper, material properties and aluminum-grade comparisons, use the AA1100 H18 material profile.
Where Does the Entry Board Sit in the Drilling Stack?
The entry board and backup board are complementary but not interchangeable. The entry sheet controls first contact at the top of the stack; the backup board supports the drill as it exits the bottom PCB panel.
Why AA1100 H18?
AA1100 is a 1xxx-series commercially pure aluminum designation, while H18 identifies a strain-hardened full-hard temper. For PCB entry use, the important procurement variables are not the alloy name alone: check the actual temper, thickness and tolerance, sheet flatness, surface cleanliness, dimensions and drilling results on the intended process.
| Specification entity | What to verify | Why buyers ask for it |
|---|---|---|
| Alloy | AA1100 / chemistry declaration | Confirms material identity |
| Temper | H18 full-hard condition | Confirms the intended work-hardened state |
| Thickness | Nominal gauge and tolerance | Affects entry rigidity and stack geometry |
| Flatness | Acceptance method and lot result | Supports uniform seating under hold-down/vacuum |
| Surface | Clean, oil-free, damage-free condition | Reduces contamination and inconsistent entry contact |
| Dimensions / edges | Panel size and dimensional accuracy | Matches tooling, loading and automatic handling |
How Should You Select 0.15, 0.18 or 0.20 mm?
Do not choose entry thickness from one hole-size table alone. The useful decision is based on the complete drilling job: smallest mechanical hole, laminate and copper construction, PCB thickness, number of panels per stack, spindle/feed condition, registration target and the backup material below the PCB.
| Thickness question | What it changes | Qualification approach |
|---|---|---|
| Thinner entry sheet | Lower material thickness before the drill reaches the PCB | Evaluate on finer holes or stacks where lower entry thickness is desired |
| Mid-range entry sheet | Balances entry rigidity and drill-through thickness | Use as a practical baseline only after checking current process history |
| Thicker entry sheet | Adds rigidity but increases material crossed before PCB entry | Evaluate for larger tools, thicker/stiffer stacks or handling needs |
Plain Aluminum vs Lubricant/Coated vs Back-Drill Entry Material
These are related entry-side products, but they should not compete for the same purchasing intent.
| Material family | Best used as | When to evaluate | YUESHAN commercial page |
|---|---|---|---|
| Plain AA1100 H18 | Standard mechanical drill-entry sheet | General PTH / multilayer jobs that pass with a plain aluminum entry | This page |
| Lubricant / coated aluminum | Entry material with a functional coating | When small-hole drilling, friction, tool wear, heat or hole-quality results justify coating | Lubricant Aluminum |
| Back-drill aluminum | Dedicated controlled-depth entry/reference material | Second-pass back drilling where residual-stub and Z-reference control are part of the qualification | Back-drill Aluminum |
Applications: Where Plain Aluminum Entry Fits
| Application | What to verify before using plain entry | Possible next step |
|---|---|---|
| Single / double-sided PCB | Hole size, panel thickness, burr and surface target | Plain AA1100 H18 is a logical first family to qualify |
| Standard multilayer PCB | Stack height, smallest drill, registration and backup support | Compare plain entry with the actual backup board |
| FPCB / rigid-flex | Panel support, cleanliness, fixture and fine-hole requirement | Evaluate thinner plain or coated entry according to line results |
| HDI / dense small-hole drilling | Tool wear, hole wall, smear/wicking and positional output | Consider lubricant/coated entry if the plain sheet is the limiting variable |
| Back drilling | Drill side, residual stub, Z-depth control and reference method | Use the Back Drilling Guide and dedicated back-drill product page |
How to Write an Aluminum Entry Board RFQ
A useful RFQ should let the supplier quote the material you actually intend to qualify.
| RFQ field | Example information to provide |
|---|---|
| Material / temper | AA1100 H18 plain aluminum entry sheet |
| Nominal thickness | 0.15 / 0.18 / 0.20 mm or your current specification |
| Sheet size | Your panel/loading dimension |
| Smallest drill diameter | Mechanical drill minimum on the target job |
| PCB construction | FR-4 / rigid-flex / high-Tg / other; layer count and board thickness |
| Panels per stack | Your qualified or target stack height |
| Current backup board | HDF / melamine / UV melamine / phenolic / other |
| Main problem | Position accuracy, burr, drill wear, surface damage, cost, consistency |
| Documents required | TDS/SDS, inspection data, sample/qualification lot, packaging details |
What Should Incoming Quality Check?
- Correct alloy/temper declaration against the purchase specification.
- Nominal thickness and agreed tolerance using the agreed test method.
- Flatness and visual condition across the usable panel area.
- Clean, undamaged surface without oil or handling contamination.
- Sheet size, squareness/edges and packaging condition.
- Lot identification and supplied TDS/SDS or inspection documents.
Send Your Current Entry-Board Specification
For a useful comparison, send the alloy/temper, thickness, sheet size, smallest drill, PCB construction, stack height and current backup board. YUESHAN can return a qualification-oriented material recommendation, TDS/SDS and sample discussion.
Aluminum Entry Board FAQ
What is a PCB aluminum entry board?
It is a thin aluminum sheet placed above the PCB panel stack during mechanical drilling. It provides a controlled first-contact surface for the drill and protects the top PCB surface.
Is 1100 H18 the same as coated aluminum?
No. AA1100 H18 describes the base aluminum alloy/temper. A coated or lubricant entry sheet adds a functional polymer/lubricating layer and should be qualified as a separate material system.
Which entry-board thickness should I use?
Choose thickness with the complete process: drill diameter, PCB construction, stack height, machine condition, registration target and backup board. YUESHAN's plain commercial range on this page is 0.15–0.20 mm.
Is a standard aluminum entry board the same as a back-drill sheet?
No. A dedicated back-drill sheet serves a controlled-depth second drilling pass and should be specified separately when residual-stub control is required.
Related Technical & Commercial Pages
AA1100 H18 Material Profile
Alloy, temper, dimensional control and material behavior.
Open material profile →Lubricant Aluminum
Functional coated entry materials for more demanding drilling conditions.
Open product hub →Back-drill Aluminum
Dedicated entry/reference material for controlled-depth back drilling.
Open product page →