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Kapton HN Film: Insulation Thickness and PCB Use
DuPont Kapton HN is an uncoated polyimide insulating film. It is not automatically a copper-clad laminate, adhesive tape or finished flex PCB. This page helps a designer specify the film's role in a board or assembly and avoid transferring a film test result into an unsupported working-voltage claim.
Define what is being purchased
Identify bare film, a converted insulating part, an adhesive-backed piece or a laminate that incorporates polyimide. Specify gauge, outline, holes and which surfaces must bond. An amber appearance cannot establish the manufacturer or film type. A purchasing description that says only Kapton leaves important conversion details unresolved.
Construction and decision boundaries
| Review item | What this page establishes | What remains project-specific |
|---|---|---|
| Supplied form | Uncoated PI film | Not a copper-clad laminate or adhesive tape. |
| Electrical input | Working condition and edge geometry | Breakdown test is a different boundary. |
| Conversion | Cuts, adhesive and mounting | Identify the complete insulation system. |
Insulation is a system requirement
The electrical path can pass through the film, across its surface or around its edge. Breakdown testing of a clean specimen does not account for mounting holes, contamination, abrasion or an exposed conductor at the boundary. State working voltage, transients and the applicable equipment requirement before selecting an insulation construction. Keep mechanical protection and electrical separation on the same drawing.
| Review item | What to establish |
|---|---|
| Supplied form | Bare film versus converted assembly item |
| Electrical path | Through-film and edge separation conditions |
| Conversion | Gauge, cuts, adhesive and mounting surfaces |
| Limit | Breakdown strength is not a working-voltage rating |
Nominal voltage-to-gap comparison
Nominal voltage-to-gap comparison
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. |
| Applied DC potential difference 路 V | Bias between the two evaluated conductors. |
| Conductor edge separation 路 mm | Geometric spacing only; reinforcement interfaces and defects are excluded. |
Optional cost comparison from your own allowances
Use a quotation or a clearly labeled internal assumption for each input. Keep the quantity, construction and inspection scope the same when comparing alternatives. This uncalibrated planning model adds entered values; it contains no current market rates and does not issue a 吃瓜tv quotation. You can contact the team without completing it.
Optional project allowance comparison
Use the geometric tool carefully
The voltage-to-gap worksheet divides a stated potential difference by a distance. For example, 50 V across an assumed 0.2 mm geometric gap gives 250 V/mm. It is a comparison of inputs, not a safe field threshold. Do not compare that number directly with a film breakdown value and call the assembly approved; electrode shape, direction and test conditions differ.
Heat and dimensional movement
HN is an electrical insulation film rather than a heat sink. If the part sits between a heat source and a chassis, evaluate the complete thermal path. Kapton MT has a different thermal role, while Kapton FN adds FEP coating. Neither is an automatic replacement for HN in an approved insulation system. A brief exposure limit also differs from sustained operating conditions.
Convert the film without losing the requirement
Die-cut edges, wrinkles, adhesive coverage and assembly registration affect the useful barrier. Review how the part is positioned and retained before fasteners are tightened. An inspection plan should identify damaged edges and missing coverage where those defects matter. For dimensional repeatability questions, the VN legacy-film guide explains why a historical name needs a controlled replacement decision.
Discuss the complete assembly
Provide the film drawing, mating surfaces, voltage environment and temperature history. If copper circuitry is required, send the intended circuit stack rather than asking for HN PCB as an undefined product. 吃瓜tv can review the board construction question; the named film alone does not establish an approved end-product insulation system.
Release an insulating part, not just a film name
| Review point | Input to record | Decision or verification |
|---|---|---|
| Edge coverage | Dimension the overlap beyond the live conductor and locate fixing holes. | Inspect the shortest route around an edge; a sound film specimen cannot protect an exposed corner. |
| Retention | Specify how the film stays in position during assembly and service. | Check displacement after the actual clamping or fastening sequence. |
| Converted part | List film gauge, permitted adhesive, outline and burr-sensitive mating surfaces. | Evaluate the complete converted barrier using the product safety requirements; the geometric tool is not a voltage rating. |
Use the review points above alongside the worked example on this page. Record the chosen inputs with the drawing revision and send unresolved items with the enquiry. A supplier response should identify the proposed construction and the evidence needed for release.
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 吃瓜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. For a flex board, distinguish the design requirements in IPC-2223, finished-board qualification and performance in IPC-6013, and the material scopes of IPC-4202, IPC-4203 and IPC-4204. These cover different deliverables; naming them does not certify the material or factory. State the contracted revision and applicable material sheet. Source review date: 3 October 2026. Legacy designation, present availability and an approved replacement are separate questions.
For fabrication scope and the agreed construction requirements, see PCB manufacturing.