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IPC-4562 specifies metal foil, not the entire laminate

IPC-4562 concerns metal foil for printed-board applications. Its procurement role is distinct from a specification for a complete copper-clad laminate or prepreg. A laminate combines a dielectric system with conductive material; the foil is one constituent. Confusing those objects can lead a buyer to request dielectric or thermal properties from a foil designation that does not define the complete board material.

The , reviewed September 29, 2026, lists IPC-4562B. Use the authorized publication to confirm designation details and the edition adopted by the purchase agreement. Older web explanations may reproduce earlier coding conventions, so do not construct a formal procurement designation by copying fragments from several revisions.

The identify foil procurement and its designation fields. This page helps organize those fields and reconcile copper quantity units. For the broader dielectric and supplier selection task, use the PCB material guide. The separation gives each page a clear purpose rather than duplicating a generic materials article under a standard number.

Identify the supplied object precisely

Begin by asking what is being purchased or specified: loose foil, carrier-supported foil, copper-clad material, or finished copper on a fabricated board. These objects can be related, but their quantity and acceptance bases are not interchangeable. A procurement request should identify the object before attaching a thickness or area-weight value to it.

Use the licensed specification and supplier documentation for formal codes, tolerances and acceptance criteria. The table above is an original review map, not a reproduced designation table. If an exact field is not yet fixed, record it as an open selection and ask the responsible engineer to resolve it instead of inventing a code that looks plausible.

Area weight and thickness answer different questions

Copper area weight describes mass spread over an area. Thickness describes a geometric dimension. They can be related through an assumed density for an ideal uniform sheet, but that relation does not replace the nominal values, tolerances or measurement rules in the adopted procurement specification. Keep the distinction especially clear when comparing a supplier's data sheet with a finished-board drawing.

For the independent calculation on this page, copper density is assumed to be 8.96 g/cm鲁. With thickness in micrometers, the corresponding area mass in g/m虏 is thickness multiplied by 8.96. One avoirdupois ounce is 28.349523125 g, and one square foot is 0.09290304 m虏. These conversion constants produce approximately 305.152 g/m虏 for 1 oz/ft虏.

Under that ideal-density model, 1 oz/ft虏 corresponds to approximately 34.057 micrometers. This is a mass-volume conversion, not an IPC nominal-thickness table and not a correction to a manufacturer's declared product specification. A familiar commercial thickness label may use a different nominal convention. Use the supplier's controlled specification for purchasing and the finished-board requirement for acceptance.

Plating, etching and other manufacturing steps separate starting foil from the final conductor. Do not put a starting-foil number into a finished-copper field without reviewing the process and the required basis. The 1 oz PCB copper and thickness guide owns that finished-board discussion. This page keeps its calculation confined to a stated copper mass and area.

Reconcile foil units and prepare the purchasing questions

Choose whether the known value is uniform copper thickness in micrometers or copper area mass in ounces per square foot. Enter the value and the net area covered by one copper layer. The tool returns the equivalent quantities under the stated density assumption and combines them with a short procurement-evidence review.

For the example of 1 oz/ft虏 over 2 m虏, the ideal copper mass is approximately 0.610304 kg. The result excludes a carrier, treatment mass, packaging, scrap, etch loss and added plating. It is not a purchased-roll weight or a manufacturing quotation. If the real quantity includes multiple layers, sum the appropriate net areas before using this single-layer basis, and retain that explanation with the calculation.

The evidence fields ask whether product identity, supplier records and the procurement reference are documented. They do not validate a grade or authenticate a certificate. A calculated mass can be correct even when the selected material is wrong for the application. The downloaded brief keeps both the arithmetic assumptions and the unresolved purchasing questions visible.

Specify the surface information the design actually uses

Surface profile matters only when its definition and measurement basis are understood. A single roughness number without a named parameter, side and method is difficult to compare. If the design or bonding process depends on a particular surface condition, identify the controlled supplier option and the evidence needed to support it. Do not assume that similar marketing labels from different vendors are exact equivalents.

RF and high-speed applications can make copper-surface selection part of a wider electrical review. However, a foil profile value by itself is not a prediction of insertion loss for an arbitrary circuit. Geometry, dielectric, frequency and the modeling convention also matter. Preserve the distinction between a material characteristic and a measured response of a completed transmission structure.

Flexible applications add a different set of questions. The foil must be considered within the actual flexible construction and movement. Naming an electrodeposited or rolled category is not enough to establish a particular motion life. Coordinate the supplier data and the mechanical use case with the flex design-standards review when movement drives the selection.

Treat substitution as a controlled decision. A purchasing alternative may match the broad thickness description while changing the surface or treatment. Identify which properties are essential to the existing design and whether supporting evidence remains representative. A lower price or a familiar grade abbreviation does not establish interchangeability.

Two offers both say 鈥渙ne-ounce copper鈥�

An illustrative buyer receives two offers with the same informal copper-weight description. One describes a foil option within a specific laminate construction; the other describes a foil product and its own surface treatment. The shared phrase does not establish that the supplied objects, dimensions or processing assumptions are the same. Compare the object and specification before comparing the price.

First, reconcile the unit basis and the controlled nominal values. Use the worksheet only to detect a likely unit mismatch, not to impose a new acceptance thickness. Then compare the exact product, manufacturing type, grade, surface information and carrier arrangement where applicable. Ask which properties are typical values and which are controlled requirements for the supplied material.

Next, identify the evidence delivered with the order. A general data sheet may explain a product family, while a lot record identifies what was supplied. Decide which records the program needs and how the material lot will be connected to fabrication. This traceability becomes useful if a later process or performance concern requires the team to reconstruct the actual construction.

Finally, record the accepted choice and the substitution rule. If the alternative is approved only after a specific review, retain that approval with the material and board revisions. Do not allow an email saying 鈥渆quivalent copper鈥� to become a permanent authorization for every future purchase without defining what equivalence means for the design.

Request useful evidence without over-specifying the wrong material

An enquiry should state the foil-related requirement and its purpose. If the concern is a bonding surface, describe that need; if it is a flexible construction or an RF performance assumption, include the relevant context. The supplier can then identify the appropriate data and any open selection, rather than responding to an undifferentiated request for 鈥淚PC copper.鈥�

When the real task is to manufacture a complete PCB, provide the controlled stackup and finished requirements rather than trying to purchase every constituent through a generic web form. The PCB Manufacturing page provides that project route. Keep the foil selections with the engineering package so that they remain visible during quotation and fabrication review.

Questions about IPC-4562