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IPC/JPCA-4104: HDI Material Scope and Legacy Drawings
IPC/JPCA-4104 is a historical specification concerning high-density interconnect material systems. It can appear on legacy drawings and material records, so engineers need to understand what the reference means before replacing it. The IPC revision table identifies the original May 1999 document as No Longer Maintained.
This page focuses on interpreting that legacy material reference and connecting it to a current project review. It does not present the old document as a universal source of modern microvia dimensions or process capability. For the manufacturing service and construction discussion, use the HDI PCB page.
Locate the original requirement in the drawing set
Find where the reference appears: material list, fabrication note, supplier qualification record or a copied template. Preserve the surrounding wording and document revision. A number copied from an old drawing may have been intended to control a material system rather than every feature of the finished board.
Identify the responsible design authority before changing it. Ask what function the original requirement was intended to protect and whether current evidence exists for the construction. This is more useful than deleting an old reference simply because a newer board technology is now available.
Legacy-reference crosswalk
| Record | Meaning | Avoid this shortcut |
|---|---|---|
| Original note | Preserve wording and intended function | Do not delete its requirement silently |
| Modern construction | Define actual openings and build sequence | Do not import an old geometry definition blindly |
| Disposition | Record approved retained or revised basis | No ratio-only reliability approval |
Separate material scope from geometry terminology
The historical document describes a particular scope and terminology. Those definitions should not be extracted into a modern universal rule without checking the current applicable design and performance requirements. A small opening does not become reliable merely because its dimensions resemble an old definition.
Record the actual build: dielectric intervals, copper layers, opening structure, target lands and sequential processing steps. Keep the selected material system and process evidence with that build. The IPC-4101 guide and scope comparison help distinguish other material-document references without assuming they automatically replace this one.
| Review item | What to establish |
|---|---|
| Legacy reference | Original wording, edition and intended material function. |
| Geometry | Depth, entrance diameter, target diameter and land definition. |
| Construction | Build sequence, filling and thermal exposure requirements. |
| Decision | Approved crosswalk and evidence; no geometry-only reliability claim. |
Dielectric opening aspect-ratio illustration
Dielectric opening aspect-ratio illustration
Use the current inputs and keep the assumptions
Start with the example only to inspect the units and the calculation boundary. Replace every assumption with a value tied to your own document or measurement. An empty numeric field is not zero. The review-reference field is a local label; avoid entering customer names, confidential part numbers or other private information into a public worksheet.
After calculating, read the notes alongside the numerical result. Changing any input invalidates the displayed result and disables its download until you calculate again. For a comparison, keep the units, geometry, material condition and measurement boundary consistent. A long decimal result does not imply equally precise input data. The downloadable record stays on your device and can be attached manually to an inquiry. It is not automatically transferred into the Contact form.
If an input is unknown, identify the person or document needed to resolve it. Do not fill a gap with a favorable generic value simply to obtain a result. You can request a material or fabrication review without using the tool. The arithmetic illustrates a relationship; it does not accept a construction, certify a material, establish current pricing or replace a supplier process specification.
| Input | What to establish before using it |
|---|---|
| Review reference | Nonconfidential revision label. |
| Opening depth 繚 繕m | Actual dielectric depth to the target land, with the drawing convention declared. |
| Declared opening diameter 繚 繕m | Choose and label entrance or minimum diameter; tapered holes have different ratios. |
Define opening depth and diameter explicitly
An aspect ratio is a geometric relationship, but it is only meaningful when its inputs are defined. A tapered laser opening has an entrance diameter and a smaller target-side diameter. The depth should identify the dielectric interval and measurement basis used by the manufacturing review.
The worksheet calculates depth divided by the entered diameter. It does not choose which diameter convention your supplier uses. Label the result accordingly. A number without that convention cannot be compared fairly with another process description, and it cannot establish an IPC limit or a plating capability.
Worked example: the same opening, two ratios
For an illustrative 60 繕m dielectric depth, a 100 繕m entrance diameter gives a ratio of 0.6. If the target-side diameter were 70 繕m, the corresponding ratio would be about 0.857. Both describe the same assumed opening using different diameter conventions.
Neither result predicts filling quality or interconnect life. The example shows why a purchasing note must preserve the measurement definition. Provide the intended profile and land geometry to the fabricator rather than comparing isolated ratios from marketing summaries or historical material references.
Review the full interconnect construction
The build sequence, copper distribution, filling and planarization requirements, stacked or staggered arrangement and subsequent thermal exposure can affect the interconnect. A material specification is one input to that construction review. It does not replace qualification of the actual structure.
Keep the approved stackup and fabrication data synchronized. If a supplier proposes changing a dielectric or opening process, identify which geometry and reliability assumptions are affected. A nominally equivalent thickness may still change processing or stress. The acceptance evidence should correspond to the released build rather than a superficially similar demonstration coupon.
Plan a controlled legacy-reference decision
A useful disposition can retain the existing contractual reference, add clarifying project requirements or replace it through an approved revision. The right choice depends on the design authority and evidence. Maintenance status alone is not enough to decide among those options.
Record the original requirement, proposed wording, content retained, rationale and approval. Keep an explicit list of unresolved issues. If a standard is replaced, do not lose the requirement it originally carried. A concise crosswalk makes the decision reviewable by purchasing and manufacturing instead of leaving it as an unexplained drawing cleanup.
Align design and acceptance documents
Rigid-board design requirements, material requirements and finished-board acceptance each have their own scope. Use the IPC-2222B design guide to understand one part of the rigid-board handoff, while retaining any additional HDI-specific project requirements.
The final drawing should define enough information for a supplier to identify the intended deliverable. Generic phrases such as advanced HDI or high reliability are not substitutes for controlled geometry, construction and evidence. A manufacturing proposal should identify exceptions before release rather than relying on the reader to infer them from a historical document title.
Prepare the feasibility review package
Send the original drawing note, its revision history if available, stackup, opening geometry, build sequence, quantity and required acceptance records. Identify whether the request is to reproduce a qualified construction or develop an alternative. Those tasks carry different technical and commercial questions.
The ratio worksheet is a discussion aid. It does not approve a microvia design or certify compliance with IPC/JPCA-4104. Attach the local result manually only if the defined dimensions help the review. 勛圖tv's response should address the actual proposed construction and evidence needed, not merely repeat the legacy standard number.
Connect the material specification to the actual HDI construction
Describe the dielectric intervals, opening geometry, copper structure and sequential processing steps together. A historical material document cannot by itself establish the reliability of a modern stacked microvia arrangement. Qualification should address the construction that will actually be built.
Keep hole definitions unambiguous: opening depth, entry and target diameters, land dimensions, plating or filling requirements and the relevant measurement location. Ask for manufacturing review of the released geometry and the agreed reliability evidence. Avoid combining a process ratio from one source with an acceptance rule from another without checking their definitions.
An inquiry is most useful when it includes layer structure, CAD outputs, build sequence, quantity and the exact unresolved requirement. Preserve changes as a reviewed stackup revision. This page provides a way to frame that discussion, not a blanket approval of every HDI design.
Standards, source context and limits
Use the edition, amendment and material-document revision named in the purchase agreement. A standards title, marketing label or supplier product family does not establish that a particular lot meets a requirement. Public summaries are useful for scope; the controlled specification and applicable test method govern acceptance.
The examples on this page are illustrative engineering scenarios. They are not 勛圖tv production records or guaranteed material values. Source links identify the organizations responsible for the referenced information. Confirm applicability to the exact grade, construction and test condition before carrying a number into a drawing or qualification report.
