AA1100 H18 is a commercially pure, strain-hardened aluminum grade used as the metal base for standard PCB drilling entry sheets. For engineering evaluation, the key items are alloy chemistry, H18 temper, tensile strength, elongation, thickness tolerance, flatness and a clean oil-free surface — not simply the words “aluminum entry board.” On the exit side of the same stack, two profiles pair with it: the lubricated backup board, which adds a lubricant layer beneath the drilled stack, and the phenolic entry board, the rigid entry alternative for fine-aperture work.
Material Profile — Not a Product Listing
This page explains the AA1100 H18 material grade and the properties engineers compare when it is used for PCB drill entry. For YUESHAN commercial sizes, qualification samples, TDS/SDS and quotations, use the PCB Aluminum Entry Sheets product page.
What Is AA1100 H18 Aluminum?
AA1100 belongs to the Aluminum Association 1xxx series of commercially pure aluminum. The Aluminum Association describes 1xxx alloys as aluminum of 99% or higher purity and identifies 1100 as a common designation in the series. H18 is a work-hardened, full-hard temper rather than a heat-treated temper.
For PCB drilling, that material identity matters because the entry layer must combine a predictable surface with sufficient rigidity, dimensional stability and thermal conductivity. The material page therefore focuses on the underlying aluminum grade; the commercial entry-board page focuses on what YUESHAN supplies.
AA1100 Chemical Composition
AA1100 is defined primarily by its high aluminum content. Published Aluminum Association-derived references and PCB-entry suppliers commonly show a minimum aluminum content of 99.0%, with silicon/iron and copper as the principal controlled residual or minor elements.
| Element / group | AA1100 reference limit | Why engineers care |
|---|---|---|
| Aluminum (Al) | ≥99.0% | Base metal; high thermal and electrical conductivity |
| Si + Fe | ≤0.95% | Main residual elements in commercial-purity aluminum |
| Copper (Cu) | 0.05–0.20% | Minor strengthening contribution |
| Manganese (Mn) | ≤0.05% | Controlled residual |
| Zinc (Zn) | ≤0.10% | Controlled residual |
| Other elements | Controlled individually / in total | Lot chemistry consistency |
Reference values are material-standard data, not a substitute for the batch certificate or YUESHAN current TDS.
What H18 Temper Means
The H temper family identifies strain-hardened aluminum. In the H18 designation, the material has been cold-worked to a full-hard condition. For a PCB entry layer, this matters because the sheet must stay flat, resist local denting and give the drill a repeatable first-contact surface.
Search terms such as 1100 H18 aluminum foil, full hard aluminum entry sheet, AA1100 H18 hardness and 1100 H18 PCB aluminum all refer to this same material grade, but performance still depends on gauge, flatness, surface finish and the drilling stack.
Mechanical Properties: UTS and Elongation
Competitive PCB-entry pages rank partly because they publish material properties rather than only sales copy. Signi, for example, publishes 1100 H18 tensile strength and elongation alongside chemistry and tolerances. Aluminum Association-derived references likewise treat tensile-property limits as part of the alloy-temper definition.
| Property | Reference value / interpretation | PCB drilling relevance |
|---|---|---|
| Ultimate tensile strength | About 150 MPa minimum in Aluminum Association-derived H18 sheet references; some PCB-entry supplier specs publish 170–190 MPa for their product range | Indicates rigidity / work-hardened condition |
| Elongation | Low in H18; depends strongly on gauge and test basis | Confirms full-hard rather than soft temper behavior |
| Density | Typical aluminum density class | Useful for material identity, not a direct drilling-quality predictor |
| Thermal conductivity | High relative to FR-4 | Helps conduct heat away from the initial drill-entry interface |
Important: use the actual YUESHAN batch/TDS values for procurement acceptance. Generic alloy values are useful for material identification, not lot release.
Thickness Tolerance, Flatness and Surface Condition
For PCB entry material, dimensional control matters more than how many alloy grades a supplier lists. High-ranking industry pages repeatedly emphasize tight thickness tolerance, flatness, dimensional accuracy, grease-free / oil-free surface and hardness. Signi publishes ±0.005 mm thickness tolerance for its 1100 H18 PCB entry sheet range. That is a useful benchmark category, but YUESHAN acceptance should follow its own current TDS and inspection data.
- Thickness / gauge: determines entry rigidity and the amount of material the drill crosses before reaching the PCB.
- Thickness tolerance: supports consistent Z geometry across the panel and lot.
- Flatness: helps the sheet seat evenly under vacuum hold-down and reduces local drill-entry variation.
- Surface cleanliness: a grease-free or oil-free surface reduces handling contamination and keeps the entry interface consistent.
- Edge and dimensional accuracy: matter for registration, tooling and automated handling.
1100 H18 Specification Quick Reference
The figures below consolidate the spec points engineers most often verify on an 1100 H18 entry sheet. They are generic material-standard and published-supplier values for evaluation; lot acceptance always follows the current YUESHAN TDS and batch certificate.
- Thermal conductivity — approx. 220 W/(m·K), more than 10× that of FR-4; this is what lets the entry sheet act as a heat sink at first contact.
- Hardness (Brinell) — approx. 20 HB at H18: hard enough to guide the bit at entry, soft enough not to dull it.
- Surface roughness — Ra ≤ 0.28 μm on a PCB-grade oil-free surface, so the sheet does not transfer contamination into the stack.
- Flatness — max deviation across the sheet diagonal of ≤ 0.10 mm for standard entry work, and ≤ 0.05 mm where back-drilling or precision microvia accuracy is specified.
- Warpage — ≤ 0.6% of the diagonal (for a 940 × 1245 mm sheet, ≤ 8.7 mm across the diagonal).
- Lot documentation — a premium-grade sheet ships with CpK documented per lot, measured across the full sheet width and length rather than at the edges only.
Grade tiers differ in inspection and selection, not in the raw alloy: a standard commercial sheet and a PCB-grade sheet can share the same chemistry, while the PCB-grade tier adds oil-free surface certification, tighter flatness screening and per-lot CpK documentation.
Lot Documents: How the COA and the Lot Number Form a Traceability Chain
The datasheet describes the grade; the certificate of analysis (COA) describes your sheet. A proper COA carries the measured values for the delivered lot — thickness, hardness, flatness — against the datasheet values, identified by lot number. A certificate that repeats the datasheet without lot values is a specification sheet, not an analysis, and it is worth saying so at RFQ rather than discovering it at incoming inspection.
Two documents complete the chain. A lot traceability statement ties the lot number to its production run and incoming material batch — batch-level traceability is the normal granularity for entry sheet, and finer granularity only if it is asked for in the order. The packing list ties the physical sheets to the lot numbers in the box, which is what makes a later claim traceable to a production run instead of an argument. Retained samples filed against the lot number close the loop: a claim backed by a filed COA against an approved revision is a short conversation.
The full document set to request per lot — and how audit access and change notification work — is set out in the supplier qualification and audit guide; the order-side sequence from first delivery inspection to standing supply is in the first-order ramp walkthrough.
How AA1100 H18 Behaves as PCB Drill-Entry Material
Placed above the PCB stack, an aluminum entry sheet provides a controlled first-contact surface for the drill. The material can help stabilize initial drill engagement, protect the copper surface and support top-side burr control. Its high-purity aluminum base also conducts heat more effectively than the laminate beneath it.
However, AA1100 H18 alone is not a complete process specification. Hole-position accuracy also depends on drill diameter, spindle speed, feed, stack height, tool condition, backup material and machine control. For process selection, use the PCB Entry Board Selector and Entry Board Thickness Calculator.
Plain AA1100 H18 covers most standard work, but once microvia precision or drill heat sets the limit, a coated grade becomes the better choice — see what a coated aluminium entry board is.
AA1100 H18 vs 1050, 1060, 3003 and 3105
Search results for PCB aluminum entry material frequently include 1050, 1060, 1100, 3003 and 3105. Those terms are useful for material comparison but should not be treated as interchangeable product names. Compare:
- aluminum purity and alloying level;
- temper / hardness condition;
- gauge and thickness tolerance;
- flatness and surface condition;
- actual drilling results under the same stack and drill parameters.
YUESHAN's standard uncoated product is based on AA1100 H18. For commercial availability, see PCB Aluminum Entry Sheets. For an engineering comparison, use the PCB Aluminum Entry Alloy Calculator.
Standards & External Technical References
- The Aluminum Association — alloy and temper standards
- Aluminum Standards & Data 2024
- IPC design standards
AA1100 H18 Material FAQ
What does AA1100 mean?
AA1100 is a 1xxx-series commercially pure aluminum designation with at least 99.0% aluminum. It is widely available as sheet and foil and is used as a PCB drill-entry base material.
What does H18 temper mean?
H18 is a strain-hardened full-hard temper. In PCB drilling, the harder condition helps the entry sheet remain flat and provide a repeatable first-contact surface.
Which properties matter most for PCB drilling?
Alloy chemistry and temper establish material identity, but thickness tolerance, flatness, surface cleanliness and actual drill-stack performance are equally important.
Is this the YUESHAN product page?
No. This is a technical material profile. For sizes, supply, samples and quotation, go to YUESHAN PCB Aluminum Entry Sheets.