勛圖tv 繚 ENGINEERING GUIDE
Pyralux AP8525E: Dielectric Spacing and Flex Timing
Pyralux AP8525E is a double-sided AP laminate identified historically with 18 繕m ED foil and 2 mil dielectric. This page addresses propagation assumptions and dielectric spacing in a flex interconnect. It does not assign a fixed impedance or interface speed from the material name.
Define the electrical route
Show the signal, return conductor, coverlay and connectors over the full path. A microstrip field can occupy both dielectric and air; a homogeneous bulk-permittivity model does not represent that geometry exactly. Keep the material test method and frequency with any dielectric number used by the field solver. Do not borrow a low-frequency value and rename it design Dk.
Construction and decision boundaries
| Review item | What this page establishes | What remains project-specific |
|---|---|---|
| Delay model | Homogeneous TEM | Not an automatic microstrip model. |
| Material input | Method and frequency-qualified permittivity | Do not transplant a table value. |
| Measurement | Declared reference planes | Connector inclusion must be stated. |
Use delay as an illustrative calculation
The tool computes ideal TEM delay from path length and a declared relative permittivity. With a hypothetical permittivity of 4 and a uniform 100 mm path, the delay is approximately 667 ps. It is not an extracted AP8525E group delay. An effective permittivity appropriate to the actual route and frequency requires a suitable model or measurement.
| Review item | What to establish |
|---|---|
| Electrical model | Return path and dielectric condition |
| Timing | Length and appropriate permittivity basis |
| Verification | Reference planes and connector inclusion |
| Limit | Homogeneous delay is not microstrip group-delay extraction |
Thickness changes more than timing
Changing dielectric spacing affects the conductor width required for a specified impedance, and that width affects resistance and copper coverage. The resulting layout can change bend stiffness as well. Resolve the stack before fixing a narrow routing channel or connector launch. Match the solver's dimensions to the fabrication drawing and tolerance basis.
Homogeneous TEM delay illustration
Homogeneous TEM delay 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. |
| Relative permittivity | Bulk material value for a homogeneous ideal TEM path; not a microstrip effective Dk. |
| Electrical path length 繚 mm | One-way uniform propagation length. |
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 勛圖tv quotation. You can contact the team without completing it.
Optional project allowance comparison
Compare the relevant neighboring construction
AP8515E covers a thinner dielectric and fine-pitch geometry. AP8525R treats the RA construction in a rigid-flex stack. For an RF route where moisture-conditioned loss is a dominant question, FELIOS LCP R-F705S provides a different polymer comparison, not an automatically equivalent laminate.
Include transitions in verification
A clean straight coupon can characterize the line while excluding the connector launch. State where the measurement reference planes lie and whether the result includes the assembled transition. If the flex is formed in use, review whether the test geometry reproduces the relevant shape, shield and nearby metal. Keep the test coupon and production route linked by a documented stack.
Request a channel-focused review
Send impedance targets, route lengths, operating frequencies, connector drawings, stack and intended installed shape. Identify permissible width or layer changes. Ask for the proposed model assumptions and verification scope with the quotation. A material data sheet and a timing worksheet are useful inputs, but neither is a complete channel qualification.
Separate propagation delay from connector discontinuities
| Review point | Input to record | Decision or verification |
|---|---|---|
| Route model | Declare whether the calculation represents homogeneous TEM propagation or a mixed-field geometry. | Treat a bulk-permittivity delay as a screening estimate when the actual field occupies air and coverlay. |
| Reference planes | Place measurement boundaries on a drawing of the complete channel. | A coupon with launches removed is not the same channel as the assembled interconnect. |
| Comparison | Keep the target impedance and operating band fixed when changing dielectric spacing. | Recalculate width, copper loss and launch geometry rather than changing delay alone. |
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 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. 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.