IPC-2222B: Rigid PCB Design and Fabrication Handoff

Place the document in the design framework

Identify the generic and sectional documents invoked by the project, together with their editions and any customer requirements. Do not assume that a reference copied from an older drawing automatically names the edition intended for a new release. Keep the design authority responsible for resolving conflicts.

A public table of contents helps establish the document's scope, but the controlled standard is needed for actual requirements. Avoid quoting an isolated dimensional rule without its class, condition or definition. A design review should preserve why a particular requirement applies to this board rather than using a standard number as a decorative compliance statement.

Geometry conventions

Translate requirements into the fabrication drawing

The supplier needs the actual layer structure, board dimensions, hole information, copper requirements, finish and relevant tolerances. A general standards note cannot fill in a missing stackup or resolve whether a hole dimension means drilled or finished diameter.

Keep the drawing, drill data, artwork and material list aligned to the same revision. If there are conflicting dimensions, identify which document controls and resolve the discrepancy before release. The stackup material-selection workflow helps connect layer geometry to the named material and thickness basis.

Geometric annular-ring allowance

Define the land and hole relationship

For an ideal circular land and concentric circular hole, the radial ring is half the difference between their diameters. If the hole center moves relative to the land, the minimum geometric ring becomes smaller on one side. Diameter tolerance and center displacement are different quantities and must not be combined ambiguously.

The worksheet accepts land diameter, maximum evaluated hole diameter and radial center displacement. It subtracts that displacement once from the concentric ring. State whether the hole input is drilled or finished and why that convention matches the requirement under review. The result is geometry only, not an acceptance-class decision.

Worked example: a nominally generous ring

Suppose the land is 0.60 mm, the evaluated hole diameter is 0.30 mm and maximum center displacement is 0.05 mm. The concentric ring is 0.15 mm and the minimum geometric ring after displacement is 0.10 mm. These dimensions are hypothetical, not a recommended pad design.

Additional land variation, etching and the applicable acceptance definition can change the review. A negative result means the entered ideal geometry extends beyond the land; a positive result still does not establish acceptance. The distinction prevents a simple calculator from becoming an unsupported design-rule checker.

Keep material specification and design geometry connected

The selected material affects the construction available to the fabricator, but a material standard does not choose every pad, hole or routing feature. Use the IPC-4101 material guide to make the procurement callout precise, then retain the actual design requirements in the drawing.

For HDI features, avoid importing a historical material definition as a universal geometry limit. The IPC/JPCA-4104 legacy-reference guide explains why scope and maintenance status need a separate review. The released structure should describe what is intended, not force the fabricator to infer it from several disconnected standard names.

Design for a reviewable tolerance chain

Identify the dimensions that interact: land size, hole size, positional variation, board thickness and registration. Use consistent worst-case or statistical assumptions. Do not add a radial tolerance as though it were a diametric tolerance, or cancel unrelated variations because their nominal values happen to align.

If a tolerance is critical, ask how it will be measured and at which manufacturing stage. A drawing requirement that cannot be interpreted consistently by design, fabrication and inspection is likely to produce avoidable questions. Record any negotiated change as a revised requirement rather than an informal shop-floor exception.

Separate design release from board acceptance

A completed design review and a passed finished-board inspection are different milestones. The design documents define the intended construction; acceptance records show what was inspected or tested against the agreed requirements. Neither milestone should be inferred from a calculator output.

Specify the acceptance scope, required records and handling of deviations before purchase. If the board is later assembled, assembly requirements and product-level tests add further boundaries. Keeping those boundaries explicit improves quotations because the supplier can identify the work and evidence included in the proposed delivery.

Send a focused DFM question

Provide the controlled fabrication package and point to the uncertain requirement. For example, identify a pad-and-hole relationship, a thickness convention or a material substitution that may affect the layout. Include quantity, acceptance expectations and whether geometry may be changed.

The local worksheet can document the arithmetic behind a question, but it does not replace a DFM review. Ask the supplier to state the proposed construction and any exceptions. Close those exceptions with the design authority before release so that the manufactured board and the intended requirement remain traceable to the same revision.

Turn a material question into a reviewable purchase requirement

A useful material callout connects the required function to a named document, a measurable condition and an approval owner. Keep the exact grade and supplied form with the thickness basis, copper treatment, test method and substitution rule. This prevents a purchasing shorthand from silently replacing a more precise engineering requirement.

Distinguish typical characterization from a guaranteed supply limit. A typical result may help compare options, but it is not automatically the acceptance value for an incoming lot. If a supplier proposes an alternative, compare the properties that affect this design and the manufacturing evidence needed to use it. Record the decision with a drawing or material-list revision instead of leaving it only in an email thread.

For an inquiry, provide the construction, required quantity, application conditions and any nonnegotiable specification references. Ask which requirements need additional evidence or lead time. A clear open question usually produces a more useful response than a broad request for the best laminate.